To link to the entire object, paste this link in email, IM or documentTo embed the entire object, paste this HTML in websiteTo link to this page, paste this link in email, IM or documentTo embed this page, paste this HTML in website

Integrated orchard management guide for commercial apples in the Southeast

Integrated orchard management guide for commercial apples in the Southeast

2011 Integrated Orchard Management Guide
for Commercial Apples in the Southeast
Alabama Cooperative
Extension System
Auburn University
University of Arkansas
Division of Agriculture
Cooperative Extension Service
University of Arkansas
Clemson Cooperative
Extension Service
Clemson University
University of Georgia Cooperative
Extension Service
University of Georgia
North Carolina Cooperative
Extension Service
North Carolina State University
University of Tennessee
Agricultural Extension Service
University of Tennessee
Poison Control Centers and Emergency Facilities
PESTICIDE POISONING B Symptoms of pesticide poisoning may include
headache, blurred vision, weakness, nausea, cramps, diarrhea, and chest discomfort.
If any of these symptoms occur during or after mixing or applying pesticides or if an
unintended unprotected exposure such as a spill occurs, stop work at once and take
appropriate action. If pesticide is spilled on the skin, immediately wash the area
thoroughly with large amounts of soap and water. If pesticide is in the eye, flush the
eye for 15 minutes in running water. If pesticide is inhaled, move to open, clean air.
If pesticide is ingested, rinse out the mouth. Follow all label first aid directions. Give
CPR if indicated. Get help. Contact your physician or poison control center (listed
below or on WPS safety poster). Transport the victim to the closest medical care
facility. Take the pesticide container or the label with you, or have others search for
the label and get it to the facility.
Most pesticide poisonings are due to overexposure to organophosphate and
carbamate insecticides. Investigation indicates these are the result of misuse,
disregard for safety precautions, and lack of proper hygiene during mixing and
application. Ninety percent of occupational exposure is through the hands. Use
neoprene or butyl rubber gloves. Rubber boots prevent acute exposure from spills
and chronic exposure from accumulation of residues in materials of boots and shoes.
STATE-DESIGNATED POISON CENTERS
Dialing 1-800-222-1222 reaches the poison control center for the state from which the call is made.
ALABAMA
Alabama Poison Center
2503 Phoenix Drive
Tuscaloosa, AL 35405
800-222-1222
800-292-6678
NORTH CAROLINA
Carolinas Poison Center
Carolinas Medical Center
PO Box 32861
Charlotte, NC 28232
800-222-1222
800-848-6946
ARKANSAS
Poison and Drug Information Center
Univ. of Ark. for Medical Sciences
4301 West Markham – Slot 522
Little Rock, AR 72205
800-222-1222
800-376-4766
SOUTH CAROLINA
Palmetto Poison Center
College of Pharmacy
University of South Carolina
Columbia, SC 29208
800-222-1222
GEORGIA
Georgia Poison Center
Education Dept
80 Jesse Hill Jr. Drive, SE
Atlanta, GA 30303
800-222-1222
404-616-9287 (for the deaf)
404-616-9000 (business)
TENNESSEE
Tennessee Poison Center
1313 21st Avenue South
Nashville, TN 37232-4632
800-222-1222
2011 Integrated Orchard Management Guide for Commercial Apples in the Southeast
Table of Contents
Pest and Orchard Management Program......................................................... 2
Tree Row Volume: A Model for Determining Spray Volume...................... 30
IPM Practices for Selected Pests................................................................... 32
Pesticide Resistance Management ................................................................ 37
Effect of pH on Pesticide Activity ................................................................ 39
Orchard Floor Management.......................................................................... 40
Apple Pollination, Honey Bees, and Pesticides ............................................ 42
Soil and Plant Analysis Guidelines for Southeastern Apple Production....... 43
Fertility Management Recommendations for Apples ................................... 44
Relative Effectiveness of Fungicides............................................................ 45
Relative Effectiveness of Insecticides and Miticides.................................... 48
Toxicity of Pesticides to Beneficial Arthropods ........................................... 50
Weed Response to Preemergence Herbicides ............................................... 51
Weed Response to Postemergence Herbicides ............................................. 52
Fungicides and Bactericides ......................................................................... 54
Insecticides and Miticides............................................................................. 57
Herbicides ..................................................................................................... 63
Growth-Regulating Chemicals...................................................................... 67
Vertebrate Management................................................................................ 74
Pesticide Safety............................................................................................. 80
EPA Registration Numbers of Various Materials ......................................... 81
Recommendations for the use of agricultural chemicals are included in this
publication as a convenience to the reader. The use of brand names and any
mention or listing of chemical products or services in this publication does not
imply endorsement by the Cooperative Extension Service nor discrimination against
similar products or services not mentioned. Individuals who use agricultural
chemicals are responsible for ensuring that the intended use complies with current
regulations and conforms to the product label. Be sure to obtain current
information about usage regulations and examine a current product before
applying any chemical. For assistance, contact your local Extension Agent.
Senior Editor: Jim Walgenbach, Extension Entomologist, N.C. State University
Section Editors:
Insect Management Jim Walgenbach
Cultural/Growth Regulators Steve McArtney
Disease Management Turner Sutton
Vertebrate Management Dave Lockwood
Weed Management Wayne Mitchem
Soils and Nutrition Ron Gehl
Contributors
Alabama South Carolina
Bobby Boozer
Ed Sikora
Horticulture
Plant Pathology
Bob Bellinger
Mike Hood
Desmond Layne
Guido Schnabel
Safety
Apiculture
Horticulture
Plant Pathology
Arkansas Tennessee
Donn Johnson
Curt Rom
Elena Garcia
Entomology
Horticulture
Horticulture
Steve Bost
Edward Burgess
Frank Hale
Dave Lockwood
John Skinner
Plant Pathology
Safety
Entomology
Horticulture
Apiculture
Georgia
North Carolina
Phillip Brannen
Keith Delaplane
Paul Gulliebeau
Dan Horton
Harold Scherm
Plant Pathology
Apiculture
Safety
Entomology
Plant Pathology
Ron Gehl
Steve McArtney
Wayne Mitchem
Mike Parker
Turner Sutton
David Tarpy
Steve Toth
Jim Walgenbach
Soil Science
Horticulture
Horticulture
Horticulture
Plant Pathology
Apiculture
Safety
Entomology
2
Pest and Orchard Management Program
DORMANT
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Cultural Management
Control tree density, size,
and shape for better light
and spray penetration.
Conduct annual dormant
pruning in central leader
trees and appropriate high-density
orchards.
*****
The younger the trees, the closer to bud break
they should be pruned. Prune older and bearing
trees first; prune 1- to 2-year-old nonbearing
trees during the month before dormant bud
break.
Provide proper nutrition
for moderate tree growth
and good fruit quality.
Collect soil samples;
establish and maintain a
good lime and fertility
program. Apply late winter
fertilizer to young,
nonbearing trees, and half
rate to mature, bearing trees.
*****
See Fertility Management section (page 44) for
complete sampling, fertilizer rates, and
application methods. Apply full rate to young,
nonbearing trees to promote good tree growth.
Increase lateral bud break
and lateral shoot
development on last
year’s leader growth to
encourage scaffold limb
development.
Bag last year’s leader growth
3 to 4 weeks before
anticipated dormant bud
break.
*****
See Growth-Regulating Chemicals section
(page 67) for details.
Plant Growth Regulators
Control water sprout
regrowth near pruning
cuts and on tops of large
scaffold limbs exposed to
light by heavy dormant
pruning.
Tre-Hold A-112
See comments.
Use 10,000 ppm (10
oz/gal) as a “sponge-on”
application.
12
0
See Growth-Regulating Chemicals section
(page 67) for complete recommendation
details. The need for this practice depends on
heaviness of pruning, size of cuts, and potential
growth vigor. Effectiveness depends on
COMPLETE coverage.
Control burr knot
formation.
Gallex
**
Paint directly from can,
full strength, on burr
knots.
See Growth-Regulating Chemicals section
(page 67) for recommendation details.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
3
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Reduce inoculum of apple
scab fungus.
Shred leaves with flail
mower.
*****
May also help reduce inoculum of fungi that
cause Brooks spot, Alternaria blotch, and
Glomerella leaf spot.
Reduce inoculum of
black, white, and bitter
rot fungi.
Prune out dead wood and
mummied fruit.
*****
Pruning is extremely important to reduce the
likelihood of these diseases. Don=t stockpile
prunings near orchard. Remove and burn, or
chip with a flail mower.
Reduce inoculum of fire
blight bacteria.
Prune out cankers and old
fire blight strikes.
****
Will also reduce inoculum of black rot, white
rot, and bitter rot.
Reduce inoculum of
powdery mildew fungus.
Prune out silver-colored
terminals.
***
Particularly useful on young trees of a
susceptible cultivar.
Improve control of cedar
apple and quince rusts.
Scout orchard, adjacent
woods, or borders for red
cedar, and remove.
*****
Complete removal of red cedar in areas where
cedars are not common may eliminate need for
fungicide sprays for these diseases.
Create good conditions
for drying fruit and
foliage; improve spray
penetration.
Prune to open trees.
*****
Pruning is extremely important for good
disease control inside the canopy and in the
tops of large trees.
Weed Management
Control seedling
perennials and winter
annuals.
Apply glyphosate or
glyphosate + 2,4-D amine or
paraquat or Rely to control
emerged winter annuals.
*****
+++++
See product label.
See product label.
Apply nonselective postemergence herbicide
alone (mid March). When control from this
breaks and summer weeds are 2-3 inches tall,
apply a nonselective postemergence herbicide
with a preemergence herbicide. This will likely
be in early May, but may vary from year to
year. Delaying PRE herbicide application
results in residual control later in the summer.
Reduce dandelions.
2,4-D amine
++++
1 qt
1.0 lb
48
60 Apply at least 2 weeks before bloom to control
flowering weeds. Reduces competition with
apple blossoms to enhance bee pollination.
Control of flowering weeds will also help
control tarnished plant bug.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
4
SILVER TIP
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Control fire blight.
Bactericides
copper hydroxide
copper oxychloride sulfate
Bordeaux
++++
++++
++++
See label.
See label.
See label.
See label.
See label.
See label.
This treatment will help control fire blight in
blocks of trees of a susceptible cultivar where
fire blight has been a problem. It will not
eliminate need for streptomycin. Applications
later than 0.25- to 0.5-inch green tip may result
in injury. Most effective if applied dilute.
Control black rot.
Fungicides
Captan 50W or
4L or
80W or
80WDG
++++
++++
++++
++++
—
—
4 lb
2 qt
2.5 lb
2.5 lb
96
96
24
24
0
0
0
0
An important spray for black rot control in
Georgia. Warning: Captan will cause injury
when used with or too close to oil applications.
Fungicides
Ridomil Gold EC or WSP
++++
See label.
12
1
Aliette 80WDG or 80 WSP
++++
⅝ to 1½ lb
2 to 5 lb
12
14
Ridomil and Aliette applications are
recommended on cultivars propagated on
susceptible rootstocks planted in heavy or
poorly drained soils. Apply Ridomil in the
spring before growth starts, and repeat
application after harvest. Apply 3 to 5
applications of Aliette a year. Make first
application of Aliette after leaf emergence.
Note: Ridomil and Aliette must be applied on a
preventive basis. Treatment of trees exhibiting
symptoms will not prevent further symptom
development.
Control crown rot
(collar rot).
Phosphite fungicides
++++
See label.
Phosphite fungicides (i.e. Prophyt, Agri-Fos,
and others) are registered for crown rot control
and have activity similar to Aliette. See labels
for use instructions and precautions.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
5
GREEN TIP TO ½-INCH GREEN
Rate Per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Fungicides
Syllit 3.4FL
+++++
1.5 to 3 pt
48
7
Vangard 75WG
+++++
1.25 oz
5 oz
12
72
Vangard 75WG
+ mancozeb
80WP or
75DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
¾ oz
¾ lb
¾ lb
0.6 qt
¾ lb
3 oz
3 lb
3 lb
2.4 qt
3 lb
12
24
24
24
24
72
77
77
77
77
Vangard tends to be most active at cool
temperatures.
Scala SC
+++++
1.75 to 2.5 oz
7 to 10 oz
12
72
Scala SC
+ mancozeb
80WP or
75DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
1.25 oz
¾ lb
¾ lb
0.6 qt
¾ lb
5 oz
3 lb
3 lb
2.4 qt
3 lb
12
24
24
24
24
72
77
77
77
77
Scala SC is not compatible with captan.
Sovran 50WG
+++++
1 to 1.6 oz
4 to 6.4 oz
12
30
Flint 50WG
+++++
—
2 to 2.5 oz
12
14
Control scab.
See discussion in
Fungicides and
Bactericides (page 54)
for information on
postinfection control
program.
Pristine 38W
+++++
—
14.5 to 18.5
oz
12
0
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
6
GREEN TIP TO ½-INCH GREEN (continued)
Rate Per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
fenarimol 1E
+ captan 50WP or
80W or
80WDG
or
+ mancozeb
80WP or
75DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
3 to 4 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
8 to 12 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
30
0
0
77
77
77
77
myclobutanil 40W
+ captan 50W or
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
1¼ to 2 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
5 to 10 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
14
0
0
77
77
77
77
Control scab (continued).
Procure 50WS
+ captan 50W
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
1 to 2 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
4 to 8 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
14
0
0
77
77
77
77
Do not use captan within 2 weeks of an oil spray.
Although resistance of the apple scab fungus to
the EBI fungicides has not been confirmed, some
growers have experienced problems in the
Southeast in controlling scab when using these
fungicides. Growers who have had this problem
should use a program that begins with two sprays
of Syllit, Vangard, or Scala, followed by two
sprays of Flint or Sovran. The fifth spray, which
should occur around petal fall, can include an
EBI fungicide, but it needs to be combined with a
full rate of captan or captan + mancozeb or
metiram to ensure scab control. An EBI fungicide
at this time will help control powdery mildew,
especially on mildew-susceptible varieties, and
cedar apple and quince rust if captan is used
alone.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
7
Rate Per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
Control scab (continued).
Indar 75WSP
+ captan 50W
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
0.67 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
2.67 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
14
14
14
77
77
77
77
Tebuzole 45DF
+ captan 50W
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
+++++
1 to 2 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
2 to 8 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
5
96
24
24
24
24
24
24
75
14
14
14
77
77
77
77
Topguard 1.04SC
+ captan 50W
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
3.2 fl oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
13.0 fl oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
14
14
14
77
77
77
77
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
8
GREEN TIP TO ½-INCH GREEN (continued)
Rate Per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
Control scab (continued).
Inspire Super MP
+ Vangard WG
+++++
1.0 fl oz
1.0 oz
4.0 fl oz
4.0 oz
12
72
In orchards where EBI resistance is suspected
Inspire Super MP + Vangard WG should
always be combined with mancozeb or
metiram.
Adament 50W
+++++
1 to 1.25 fl oz
4 to 5 oz
5
75
Adament is a prepack combination of
tebuconazole (an EBI fungicide) +
trifolxystrobin (a QoI fungicide). Do not
make more than 4 applications per season.
Insect Management
Control scales and reduce
overwintering European
red mite and rosy apple
aphid eggs.
Insecticides
Oil
+++++
2 gal
2 to 3%
solution
12
0
Use either a superior-type or highly refined
summer oil applied dilute. If the oil
application is delayed until tight cluster to
pink, use a refined oil or reduce a superior
type to ½ to 1 gal/100 gal. Do not use captan
within 2 weeks of an oil application.
Improve scale control.
Oil +
Lorsban 4E
or
Esteem 35WP
or
Diazinon 50WP
++++
+++++
++++
2 gal
½ to 1 pt
—
1.0 lb
8 gal
2 to 4 pt
4 to 5 oz
4 lb
12
96
12
96
0
DD
45
21
An insecticide with oil may be added at this
time in orchards experiencing problems with
scales. This option is recommended in
orchards that experienced scale problems the
previous year.
Initiate Oriental Fruit
Moth (OFM) monitoring
program.
Erect pheromone traps
*****
Erect pheromone traps by green tip to detect
first emergence. See section on IPM Practices
for Selected Pests (page 32) for monitoring
information.
Mating disruption for
OFM and codling moth.
Pheromones
Isomate CM/OFM TT
CideTrak CM/OFM
CheckMate Puffer -
CM/OFM
Isomate CM/OFM Ring
+++++
+++++
+++
+++
(# dispensers)
200/acre
200/acre
1/acre
20/acre
Now is the time to begin erecting pheromone
dispensers for mating disruption.
Combination dispensers that contain both
OFM and codling moth pheromone are
recommended. Hanging of dispensers in trees
should be complete by petal fall. See section
on “Mating Disruption�� in IPM Practices for
Selected Pests (page 34).
9
TIGHT CLUSTER TO PINK
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Control scab.
Fungicides
Same as used in green-tip
spray.
If two sprays of Sovran, Pristine, or Flint were
used, switch to a nonstrobilurin fungicide.
Syllit, Scala, and Vangard are most
effectively used in the first two sprays of the
season.
Control powdery mildew.
Fungicides
myclobutanil 40W
fenarimol EC
Procure 50WS
Indar 75WSP
Tebuzole 45 DF
Topguard 1.04SC
++++
++++
++++
++++
++++
+++++
1¼ to 2 oz
3 to 4 oz
1 to 2 oz
0.67 oz
1 to 2 oz
2 to 3 oz
5 to 10 oz
8 to 12 oz
4 to 8 oz
2.67 oz
2 to 8 oz
8 to 12 oz
24
12
12
12
5
12
14
30
14
14
75
14
These are the most important sprays for the
control of powdery mildew.
Control cedar apple rust
and quince rust.
Fungicides
Same as used for
powdery mildew, or:
mancozeb 80W or
75DF or
F4
Polyram 80W
+++++
+++++
+++++
+++++
¾ lb
¾ lb
0.6 qt
¾ lb
3 lb
3 lb
2.4 qt
3 lb
24
24
24
24
77
77
77
77
Control black rot and
frogeye leafspot.
Captan 50W or
4L or
80 W or
80WDG
++++
++++
++++
++++
1½ to 2 lb
¾ to 1 qt
0.94 to 1.26 lb
0.94 to 1.26 lb
6 to 8 lb
3 to 4 qt
3.77 to 5 lb
3.77 to 5 lb
96
96
24
24
0
0
0
0
Captan alone will not control powdery
mildew or rust diseases.
Insect Management
Initiate codling moth and
leafroller monitoring
program.
Erect pheromone traps.
*****
Erect traps now because moths begin to
emerge near bloom. See section on IPM
Practices for Selected Pests (page 32) for
information on monitoring programs.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
10
TIGHT CLUSTER TO PINK (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv
Interval
(days) Comments
Control rosy apple
aphid.
Insecticides
Actara 25WDG
Assail 30SG
Calypso 4F
Diazinon 50W
Danitol 2.4EC
+++++
+++++
+++++
+++
++++
—
—
—
1 lb
2.6 to 4.3 oz
4.5 oz
2.5 to 4 oz
2 to 4 oz
4 lb
10.6 to 21.3 oz
12
12
12
24
24
35
7
30
21
14
Pink stage is the best time to control rosy
apple aphid. Caution: Rosy apple aphid
resistance to Diazinon and Danitol has been
observed in some orchards. See Rosy Apple
Aphid resistance section (page 38).
Assail may be used during bloom if sprays
are applied before or after bees are in the
orchard. Assail residues on leaves or
flowers are not toxic to bees, but avoid
spraying when bees are in the orchard.
Control plant bugs
and spotted tentiform
leafminer (STLM).
Maintain clean ground-cover.
Insecticides listed for
rosy apple aphid will aid in
plant bug and leafminer
control if plant bugs are
readily seen.
*****
In many instances, a clean groundcover
eliminates the need for insecticides to
control bugs. If there is a history of plant
bug problems, a second application at petal
fall will improve control. The need for
insecticides specifically targeting STLM at
this time is questionable because first
generation mines rarely exceed threshold
levels.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
11
BLOOM
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Cultural Management
Loosen bags on leaders to
acclimate for 2 to 3 days;
then remove bags from
leaders and spray with
Promalin or Perlan.
Leader bags must be
removed when new lateral
growth is 1” to 3” long.
*****
See Growth-Regulating Chemicals section
(page 67) for complete details.
Do leader selection and
strip whorl on dormant
headed tree leaders.
Select new shoot for
central leader and remove
competing shoots from
first four nodes below new
leader shoot.
Plant Growth Regulators
Improve fruit shape and
increase fruit weight of
Red and Golden
Delicious (can be used
only on varieties that
have dominant calyx
ends).
(BA+GA 4 + 7)
Promalin
Perlan
+++
+++
0.5 to 1.0 pt
1 to 2 pt
12
4
None
See Growth-Regulating Chemicals section
(page 67). Apply as a fine mist application
at 40 to 50% of Tree Row Volume (TRV)
water rate between king bloom opening and
full bloom.
Increase lateral bud break
and lateral shoot growth
on 1-year-old leader
growth as a tool to
encourage scaffold limb
development, especially
on those that were bagged
before bud break. Use on
nonbearing trees only.
Promalin
Perlan
+++++
+++++
250 to 500
ppm
(1 to 2 pt)/10
gal
125 to 500
ppm
(0.5 to 2 pt)/
10 gal
12
4
None
Apply to last year’s leader growth with a
handheld nozzle. See Growth-Regulating
Chemicals section (page 67).
Make one application when orchard trees
have 1 to 3 inches of new growth.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
12
BLOOM (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Control scab, rusts, and
mildew.
Fungicides
Same fungicides as
recommended in tight
cluster stage.
Avoid sprays in full bloom if possible. Do not
overextend application intervals.
Control fire blight.
Bactericides
streptomycin
4.8 to 8 oz
1½ to 2½ lb
12
50
Begin application at first bloom and continue at
3- to 4-day intervals until petal fall.
Streptomycin sprays protect only those
blossoms open at time of application. It is very
important to continue spraying through “rat-tail”
bloom, especially on susceptible varieties.
See discussion under Pesticide Resistance
Management section (page 38) for timing
sprays according to conditions favorable for
infection.
Insect Management
Protect pollinators.
Do not apply insecticides
during bloom.
*****
Keep orchard floor free of flowering weeds.
This will increase pollination activity in the
trees and lessen bee activity after apple bloom.
Disrupt mating of codling
moth.
Pheromones
Isomate CM/OFM TT
CideTrak CM/OFM
CheckMate Puffer -
CM/OFM
Isomate CM/OFM Ring
+++++
+++++
+++
+++
(# dispensers)
200/acre
200/acre
1/acre
20/acre
Do not use mating disruption in blocks of less
than 5 acres. Pheromone dispensers should be
hung before moths begin to emerge, with
hanging completed by petal fall. Also,
supplemental sprays with an insecticide will be
necessary under moderate to high population
densities. See section on IPM Practices for
Selected Pests (page 32).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
13
PETAL FALL
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Cultural Management
Reduce fruit corking.
Solubor
Borosol
+++
+++
1 lb
at first cover
1 pt
If boron is low in leaf sample or cork spot has
been a problem in past years, a second and
third application may be used. Dilute
applications are necessary for good uptake. See
Fertility Management section (page 44).
Reduce fruit corking and
bitter pit.
calcium nitrate
or
calcium chloride
+++
+++
3 lb
2 lb
beginning at
first cover
Repeat calcium sprays in each cover spray all
season. Calcium nitrate may contribute to
elevated leaf nitrogen levels and vegetative
growth. Do not apply calcium chloride when
temperatures are above 85°F, and DO NOT
tank mix with Solubor or Apogee. All calcium
sprays should be applied dilute for maximum
response, especially for bitter pit control in late
season cover sprays when fruit are becoming
waxy. See Fertility Management section (page
44).
Plant Growth Regulators
Reduce fruit russetting on
susceptible cultivars (esp.
Golden Delicious).
(GA4+7)
Pro-Vide 10SG
Novagib 10L
++++
++++
60 - 100 g
20-26 fl oz
12
4
None
At petal fall, begin the first of four applications
at 7- to 10-day intervals. See Growth-
Regulating Chemicals section (page 67) for
complete recommendations.
Thin fruit to reduce crop
load and encourage return
bloom.
Depends on cultivar, fruit
size, and thinning chemical
selected. Applications
timed from petal fall to
about 8 mm would be
applied during this time.
+++++
See thinning
chart on page
70.
Check label for specific
thinning chemical(s) to
be used.
See Chemical Fruit Thinning Spray and Apple
Thinning recommendations chart in Growth-
Regulating Chemicals section.
Initiate vegetative growth
control applications.
Apogee
++++
Use at TRV
calculated
A.I./acre.
12
45
See Apogee table in Growth-Regulating
Chemicals section (page 72).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
14
PETAL FALL (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Control scab.
Scout for secondary scab.
*****
If primary scab is controlled by petal fall or
first cover, switch to captan. If secondary scab
is detected early, dodine or an EBI fungicide
can be effectively used in a postsymptom
treatment. See discussion under Fungicides and
Bactericides (page 54).
Fungicides
captan 50W or
4L or
80W or
80WDG
2 lb
1 qt
1.25 lb
1.25 lb
8 lb
4 qt
5 lb
5 lb
96
96
24
24
0
0
0
0
If an EBI fungicide is used in this spray,
increase the rate of Captan 50W to 6 to 8
lb/acre or Captan 4L to 3 to 4 qt/acre and
extend interval to 10-14 days, or follow
combination sprays with lower rates of captan
or metiram in 5-7 days with full rate of captan
or combinations of captan plus mancozeb or
metiram. Captan and metiram at petal fall or
first cover generally give better fruit finish than
mancozeb. If the first cover spray occurs after
May 15, include 8 to 12 oz/acre of thiophanate-methyl
85WDG with captan for sooty blotch or
flyspeck control as directed in second and later
cover sprays below. Use captan in orchards
where black rot is a problem.
Control summer diseases
(general).
captan 50W or
4L or
80 W or
80 WDG
+
Polyram 80 W or
mancozeb
80W
75 DF
4F
+++++
+++++
+++++
+++++
+++++
1¼ lb
0.62 qt
0.79 lb
0.79 lb
¾ lb
¾ lb
¾ lb
0.6 qt
5 lb
2½ qt
3.15 lb
3.15 lb
3 lb
3 lb
3 lb
2.4 qt
96
96
24
24
96
96
96
96
0
0
0
0
77
77
77
77
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
15
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control summer diseases
(general) (continued).
Sovran 50WG
+++++
1.0 to 1.6 oz
4.0 to 6.4 oz
12
30
Sovran and Flint will also control apple scab
and powdery mildew.
Flint 50WG
+++++
—
2.5 to 3.0 oz
12
14
Pristine 38W
+++++
—
14.5 to 18.0 oz
12
0
Control Brooks fruit spot.
Fungicides
Use fungicides listed for
summer diseases or use
fungicide combinations
listed under green tip.
+++++
Petal fall through third cover sprays are the
most important sprays for Brooks spot control.
The EBI fungicides have very little Brooks
spot activity. If one of them is used, combine it
with a full rate of protectant.
Control powdery mildew
and cedar apple rust.
Fungicides
See tight cluster to pink
spray.
If captan alone is used in these sprays, a
fungicide with activity on powdery mildew or
cedar apple rust should be included in this
spray.
Insect Management
Preventively control
European red mite,
spotted tentiform
leafminer, and white
apple leafhopper.
Insecticides
Agri-Mek 0.15EC
+
oil
+++++
2.5 oz
10 oz
12
28
An application of Agri-Mek at petal fall should
provide season-long suppression of these pests.
A paraffinic spray oil (0.25% or 1 gal/acre)
must be tank mixed to ensure Agri-Mek’s
activity. Do not use captan 2 weeks before or
after applying oil with Agri-Mek.
Preventive control of
European red mite.
Apollo SC
Savey 50WP
Zeal 72WDG
Envidor 2SC
++++
++++
+++++
+++++
—
—
—
—
4 oz
3 oz
2 to 3 oz
16 to 18 oz
12
12
12
12
45
28
28
7
Apply one of these products between petal fall
and third cover or when mites reach one adult
per leaf. See page 38 for resistance
management of European red mite.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
16
PETAL FALL (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control plum curculio.
Insecticides
Avaunt 30WG
Actara 25SDG
Guthion 50WP
Imidan 70WP
Calypso 4F
Clutch 50WDG
Sevin 50WP
+++++
+++++
+++++
++++
++++
+++
+++
—
—
½ lb
¾ lb
—
—
½ lb
5 to 6 oz
4.5 to 5.5 oz
2 lb
3 lb
4 to 8 oz
3 oz
1 lb
12
12
48h, 14d
24
12
12
12
28
35
21
7
30
14
3
Adults begin to enter orchards near bloom,
with the majority of adults present by petal fall.
An insecticide applied at petal fall is essential
to minimize damage. Cool weather during this
period may extend adult activity, which may
require a second application 10 days later.
Read about re-entry intervals for Guthion in the
Insecticides and Miticides section (page 57).
Control Oriental fruit
moth.
Insecticides
Guthion 50WP
Imidan 70WP
Avaunt 30WG
Sevin 50WP
Assail 30SG
Calypso 4F
Clutch 50WDG
+++++
++++
++++
++++
++++
++++
+++
½ lb
¾ lb
—
½ lb
—
—
—
2 lb
3 lb
5 to 6 oz
2 lb
5 to 8 oz
4 to 8 oz
3 oz
48h, 14d
24
12
12
12
12
12
21
7
28
3
7
30
14
Oriental fruit moth has become more important
in apples in recent years. An insecticide
applied between 500 and 600 degree days (DD)
after biofix will control the first generation.
Read about re-entry intervals for Guthion in
Insecticides and Miticides Section (page 57).
First generation OFM is easily controlled with
all recommended insecticides.
Control San Jose scale.
Insecticides
Diazinon 50WP
Guthion 50WP
Esteem 0.86EC
Centaur 70WP
Movento 2SC
Assail 30SG
summer oil
+++++
++++
+++++
+++++
++++
+++
+++
1 lb
½ lb
—
—
—
—
—
4 lb
2 lb
4 oz
34.5 oz
6-9 oz
8 oz
1 to 2%
96
48h, 14d
12
12
24
12
12
21
21
45
14
7
7
0
Where scales have been a problem the previous
year, apply an insecticide for first generation
crawlers, which are active from petal fall
through third cover. Yellow crawlers can be
detected by wrapping double-stick tape around
infested limbs after bloom and inspecting
weekly. Caution: Diazinon or oil applied with
captan or Captec may cause phytotoxicity.
Control rosy apple aphid. Insecticides
Provado 1.6F
Actara 25WP
Assail 30SG
Calypso 4F
Movento 2SC
+++++
+++++
+++++
+++++
++++
2 oz
—
—
—
—
4 to 8 oz
4.5 oz
2.5 to 4.0 oz
2 to 4 oz
6 to 9 oz
12
12
12
12
24
7
35
7
30
7
If an insecticide was not applied for rosy apple
aphid at pink, or if control was poor, an
insecticide should be applied.
An adjuvant must be applied with Movento.
See section on Rosy Apple Aphid resistance
section (page 38).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
17
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control white apple
leafhopper.
Insecticides
Sevin 50WP
Actara 25WDG
Assail 30SG
Calypso 4F
Provado 1.6F
Avaunt 30WG
+++++
+++++
+++++
+++++
+++++
+++++
½ lb
—
—
—
1 oz
—
2 lb
2 to 2¾ oz
2.5 to 4.0 oz
2 to 4 oz
4 oz
5 to 6 oz
12
12
12
12
12
12
1
35
7
30
7
28
Threshold level for first generation white apple
leafhopper is 1 nymph per leaf. Thinning
apples with Sevin during this time controls
leafhoppers. Leafhoppers may be present from
petal fall to second cover spray.
Control spotted
tentiform leafminer.
Insecticides
Actara 25WDG
Delegate WG
Provado 1.6F
Assail 30SG
++++
+++++
++++
++++
—
—
1 to 2 oz
—
4.5 oz
4.5 oz
4 to 8 oz
1.1 oz
12
4
12
12
35
7
7
7
Threshold level for first generation leafminer is
one mine per leaf, but rarely do populations
reach this level this early in the season.
Control green
fruitworm.
Insecticides
See insecticides for codling
moth or tufted apple bud
moth control.
Green fruitworms are not a common pest:
Apply an insecticide at petal fall if larvae are
observed.
Weed Management
Control weeds.
Check orchards for weed
populations.
*****
Identify weed problems so herbicide program
can be adjusted for summer weed control.
Apply PRE +
Nonselective POST
herbicide.
See herbicide guide.
*****
See product labels.
See product labels.
Apply when summer weeds are 2 to 3 inches
tall. Delaying application of preemergence
herbicides until early May extends summer
weed control.
Suppress clover bloom
to protect bees from
insecticide sprays.
2,4-D *****
1 qt
48
60
Apply 2,4-D 7 to 10 days before spraying
insecticides to suppress clover and avoid
killing bees.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
18
FIRST COVER
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management (Same fungicides as used in Petal Fall Spray)
Insect Management
Control codling moth.
Monitor codling moth adult
activity.
Insecticides
Delegate 25WP
Altacor 35WDG
Voliam Flexi
Belt 4SC
Guthion 50WP
Imidan 50WP
Intrepid 2F
Rimon 0.83EC
Assail 30SG
Calypso 4F
CYD-X
*****
+++++
+++++
+++++
++++
++++
++++
++++
++++
++++
++++
++++
—
—
—
—
½ lb
¾ lb
—
—
—
—
—
4.5 to 7 oz
2.5 to 4.5 oz
4 to 7 oz
3 to 5 fl oz
2 lb
3 lb
10 to 16 oz
20 to 40 oz
4 to 8 oz
4 to 8 oz
1 to 3 oz
4
4
12
12
48h, 14d
24
4
12
12
12
4
7
14
35
14
21
7
14
14
7
30
0
See IPM Practices for codling moth (page
32) to determine how to minimize insecticide
applications for codling moth control.
Most insecticides generally provide 2 weeks’
control, so do not be concerned if pheromone
trap counts remain high 1 week after spraying.
If using Intrepid or Rimon (which are excellent
ovicides) for first generaton codling moth, 2
applications at 14-day intervals should be
made, the first at 100 DD.
CYD-X is a virus that controls only codling
moth. Frequent applications (7-10 days) at low
rates (1 to 2 oz per acre) have worked well in
field trials.
Codling moth insecticide-resistant populations
exist in some orchards and can affect the
performance of certain products.
Control rosy apple
aphid, plum curculio,
white apple leafhopper,
spotted tentiform
leafminer, and San Jose
scale.
Monitor orchards for these
insects.
Insecticides
(See Petal Fall section,
page 13)
*****
Infestations of these insects may occur anytime
from petal fall to the second cover spray. Early
detection is important for effective control.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
19
SECOND COVER AND LATER SPRAYS
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Cultural Management
Reduce fruit corking and
bitter pit.
calcium nitrate
calcium chloride
+++
+++
3 lb
2 lb
See information listed in Petal Fall to First
Cover sections (pages 13 through 18) and
Fertility Management section (page 44).
Apply second half of fertilizer to
mature, bearing trees if crop
load is present, as soon as
frost/freeze danger is past
(approx. second cover).
++++
See Fertility Management Recommendations
section (page 44) for fertilizer use suggestions
and complete recommendations.
Provide proper nutrition
for moderate tree growth
and good fruit quality.
Collect leaf samples in July to
mid-August for leaf analysis.
+++++
See Fertility Management Recommendations
section (page 44) for complete details.
Select lateral limbs, strip whorls,
establish wide crotch angles
with toothpicks or clothespins,
and prop limbs to good limb
angles (60-90° for central leader
trees and 75-85° below vertical
for high density, slender,
spindle-type trees).
++++
Tree training is mandatory to develop proper
lateral branching and limb position.
Achieve proper tree
training, and control tree
size and density for good
light and spray
penetration.
Do detailed young tree
management (deshoot, position
limbs, tie up leader growth)
every 6 to 8 weeks until full tree
size and bearing are achieved
(especially for high density
orchards).
++++ Summer pruning is a necessary extension of
tree training begun earlier. Summer pruning
helps contain tree size and density, and proper
limb selection and positioning encourage
flower initiation.
Remove water sprouts.
++++
Do leader manipulation, such as
summer bending or snaking,
every 18 inches of terminal
growth extension.
++
Removing upright water sprout growth reduces
tree density, allowing greater spray penetration
and better light distribution for fruit quality and
color development. Summer pruning and
removal of water sprouts also help control
sooty blotch and flyspeck.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
20
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness(+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Plant Growth Regulators
Thin to reduce crop load
and encourage return
bloom.
Depends on cultivar, fruit
size, and thinning chemical
selected. Application time
from approximately 9 mm
and larger would be applied
from second cover on.
+++++
See
thinning
chart on
page 70.
See Chemical Fruit Thinning Sprays (page 68)
and Apple Thinning Recommendations chart
(page 70) in Growth-Regulating Chemicals
section.
Enhance return bloom.
Fruitone L
Ethrel
+++
+++
2 oz
16-72
fl oz
48
96
Research studies in the Southeast have found
that NAA or Ethrel treatments can improve
return bloom. Ethrel rate depends on many
factors including cultivar and crop load. Refer
to table on page 69.
Control ground suckers
around base of trunk.
Tre-Hold A-112 Sprout
Inhibitor -
Also use herbicides approved
for sucker control. See notes
in Herbicide section (page
63) for Rely, Gramoxone.
++++
Use 10,000 ppm (10
oz/1 gal) as a low-pressure,
large-droplet
handgun application.
12
0
See Sucker Control (page 72) for specific
recommendation details.
Delay preharvest fruit
drop and delay fruit
maturity.
ReTain
+++++
2 oz
One 333-
gram
pouch per
acre (50 g
a.i.)
12
7
Single Pick Harvest. Applying one pouch of
ReTain per acre 4 weeks prior to the
anticipated beginning of the normal harvest
period of untreated fruit for the current season
will delay the harvest period by 7-10 days.
Multiple Pick Harvest. Applying one pouch
of ReTain per acre 1 to 2 weeks prior to the
anticipated beginning of the normal harvest
period of untreated fruit for the current season
will improve quality and storage potential of
later picked apples (2nd and 3rd pick fruit).
Applications at this time will not typically
delay the start of the harvest, but will help
control the maturation rate of the later harvests.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
21
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Delay or reduce
preharvest fruit drop or
both.
Preload NAA (Fruitone-L)
++++
2 oz
48
4
Apply multiple applications of 5 ppm each
week for the 4-week period prior to the
normal start of the harvest period for each
variety.
NAA (Fruitone L)
+
4 to 8 oz
48
4
Temporarily suppress any fruit drop by
applying 10 to 20 ppm (depending on
variety) of NAA. A second application can
be applied 7 to 10 days later. See Growth-
Regulating Chemicals section (page 67) for
details.
Reduce fruit russetting
in susceptible varieties.
Pro-Vide 10SG
Novagib 10L
(continue applications started
at petal fall)
++++
++++
60-100 g
20 oz per
acre/appl
12
4
0
See Growth-Regulating Chemicals section
(page 67) for recommendation details.
Pro-Vide 10SG
+++
100-200 g
12
0
Reduce fruit cracking of
susceptible varieties
(e.g., Stayman).
Novagib 10L
+++
2 to 4 pt per
acre/appl
4
Begin applications in early to mid June or
as soon as cracking is observed. Repeat at
3-week intervals until harvest. See Growth-
Regulating Chemicals section (page 67) for
details.
Promote lateral
branching of current
season=s growth.
Promalin
+++
0.8 oz/gal of
water (125 ppm)
12
None
See Growth-Regulating Chemicals section
(page 67) for recommendation details.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
22
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Scout orchard.
Prune out fire blight strikes.
*****
*****
Fungicides
captan
50W or
4L or
80W or
80WDG
+++++
+++++
2 lb
1 qt
1.25 lb
1.25 lb
8 lb
4 qt
5 lb
5 lb
96
96
24
24
0
0
0
0
Control summer diseases
(white rot, bitter rot,
black rot, sooty blotch,
flyspeck, black pox).
ziram 76DF or 76WDG
++++
2 lb
8 lb
48
14
Apply cover sprays at 10- to 14-day
intervals. Use a 7- to 10-day interval during
wet, rainy periods. If thiophanate-methyl is
not used in cover sprays, it is important to
combine captan with sufficient ziram to
increase fungicide rate to 8 to 10 lb/acre in
order to control sooty blotch and flyspeck.
Be sure to observe 77-day preharvest
interval when using metiram or mancozeb.
When using a combination of captan and
ziram, use approximately equal rates of
each. Use captan where there is a history of
white rot.
Sovran 50WG
+++++
1.0 to 1.6 oz
4.0 to 6.4 oz
12
30
A maximum of four applications and 25.6
oz of Sovran 50WG can be used per acre
per season. It is weak on black pox.
Flint 50WG
+++++
—
2.5 to 3.0 oz
12
14
A maximum of four applications and 11 oz
of Flint 50WG can be used per acre per
season. It is weak on black pox.
Pristine 38W
+++++
—
14.5 to 18.0
oz
12
0
captan
50W or
4L or
80W or
80 WDG
+
thiophanate-methyl 85WDG
+++++
2 lb
1 qt
1.25 lb
1.25 lb
2 to 4 oz
8 lb
4 qt
5 lb
5 lb
8 to 16 oz
96
96
24
24
96
0
0
0
0
1
A maximum of four applications and 72 oz
of Pristine can be used per acre per season.
Pristine has activity on strains of the
Alternaria blotch fungus that are resistant to
Sovran and Flint. It is weak on black pox.
If Captan 80W or 80WDG is used then the
REI is 48 hours for this and other
combinations below.
ziram 76DF or 76WDG
+
thiophanate-methyl 85WDG
+++++
2 lb
2 to 3 oz
8 lb
8 to 12 oz
48
14
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
23
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*) 100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control summer diseases
(continued).
captan
50W or
4L or
80W or
80 WDG
+
metiram 80DF
or
mancozeb 75DF
+++++
1.25 lb
1 pt
0.79 lb
0.79 lb
¾ lb
¾ lb
5 lb
2.5 qt
3.15 lb
3.15 lb
3 lb
3 lb
77
77
Metiram and mancozeb cannot be used
within 77 days of harvest.
captan
50 W or
4 L or
50W or
50WDG
+
ziram 76DF, 76WDG
+
thiophanate-methyl 85WDG
+++++
1 lb
½ qt
0.63 lb
0.63 lb
1 lb
2 to 4 oz
4 lb
1 qt
2.52 lb
2.52 lb
4 lb
8 to 16 oz
96
14
captan
50 W or
4 L or
80W or
80WDG
+
ProPhyt3
+++++
2 lb
1 qt
1 ¼ lb
1 ¼ lb
½ to ¾ qt
8 lb
4 lb
5 lb
5 lb
2 to 3 qt
96
0
This combination is effective on Glomerella
leaf spot. Make the first spray around June
15th or when first leaf spot symptoms
appear and continue spraying every 7-10
days until harvest. Use a 7-day interval
when it is warm and wet. Use high rate of
ProPhyt where Glomerella leaf spot is a
problem. Rotations with Pristine or Flint are
also effective.
The REI is 24 hours if Captan 80W or
80WDG is used.
Suppress necrotic leaf
blotch on Golden
Delicious.
ziram 76W or WDG
zinc oxide 39.8%
+++++
+++++
1 to 2 lb
4 to 8 lb
1 pt
48
0
14
0
Sprays from mid June through early August
are most important.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
3Other phosphite fungicides are also labeled on apples. See the discussion of phosphite fungicides in the Fungicides and Bactericides section (p. 54).
24
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
interval
(days) Comments
Control powdery
mildew.
Scout orchard.
*****
Determine need for additional fungicides
based on the number of infections on newly
unfolded leaves.
Control Alternaria
blotch.
Pristine 38W
+++++
14.5 to 18.5 oz
12
0
Make first application of Pristine around
third or fourth cover (mid June). Apply two
additional applications at 10- to 14-day
intervals. These applications will also control
other summer diseases on Delicious.
Rotations of Pristine and captan plus a
phosphite fungicide are also effective and
will help limit QoI fungicide use since only 4
sprays are allowed by the label. Use in
conjunction with a preventive mite
management program. Do not make more
than 4 applications or apply more than 72 oz
of Pristine per season.
Insect Management
Monitor pheromone traps
weekly for adult activity.
*****
Insecticides
(See First Cover.) *****
Control codling moth
and Oriental fruit moth.
OFM Mating Disruption
Isomate-M100
CheckMate OFM-F
+++++
+++++
100
1 to 2 oz
See IPM practices for codling moth (page
32) and Oriental fruit moth (page 33) to
determine the need for and timing of
insecticide sprays. Keep trap bottoms clean,
and replace lures at recommended intervals.
If a combination codling moth/Oriental fruit
moth mating disruption product is not used,
OFM populations often increase later in the
season (August and September). Isomate-
M100 applied in June or sprays of
CheckMate OFM-F in July and/or August
will usually control late-season populations.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
25
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control tufted apple
bud moth.
Monitor pheromone traps
weekly for adult activity.
Thin fruit to avoid
excessive clustering.
*****
****
See IPM Practices for tufted apple bud moth
(page 34) to determine the proper timing of
insecticide applications.
Clustering of fruit is conducive to higher
levels of tufted apple bud moth injury.
Insecticides
Intrepid
Delegate 25WG
Altacor 35WDG
Voliam Flexi
Belt 4SCV
+++++
+++++
+++++
+++++
+++++
—
—
—
—
—
6 to 12 oz
4.5 to 7 oz
2.5 to 4.5 oz
4 to 7 oz
3 to 5 fl oz
4
4
4
12
12
14
7
14
35
14
See Insecticide Resistance Management
section (page 37) for tufted apple bud moth
(TABM). Insecticide sprays for TABM are
recommended only in orchards with a history
of damage. See section on IPM practices for
TABM (page 34) to properly time sprays.
Bacillus thuringiensis
Dipel 2X
CryMax
XenTari
+++
1 to 2 lb
1 to 2 lb
1 to 2 lb
4
4
4
0
0
0
For best results apply Bacillus thuringiensis
(Bt) products at no less than 2X
concentration. If using Bts, it is important
to monitor codling moth with pheromone
traps because Bts do not control CM.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
26
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control apple maggot.
Erect red sticky spheres in
early June to monitor
adults.
****
Erect sticky traps baited with fruit essence
lures on outside rows nearest abandoned
orchards or other sources of flies. Check
weekly. Threshold level is a cumulative of 5
flies per trap. If the threshold is exceeded
again 2 weeks after spraying, apply again.
Adults can emerge from June through
September. Historically, peak emergence
generally occurs from mid July to early
August.
Insecticides
Guthion 50WP
Imidan 70WP
Assail 30SG
Calypso 4F
Provado
Surround WP
+++++
++++
+++
+++++
++++
+++
½ lb
¾ lb
—
—
—
—
2 lb
3 lb
8 oz
4 to 8 oz
6 to 8 oz
20 to 50 lb
48h, 14d
24
12
12
12
4
21
7
7
30
7
C
Apply Surround at 7- to 14-day intervals, or
after a heavy rain, because thorough,
uniform, and consistent coverage is
important. Rate of Surround will vary with
tree size.
Control white apple
leafhopper or potato
leafhopper.
Insecticides
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Avaunt 30WG
Clutch 50WDG
Centaur 70WP
+++++
+++++
+++++
+++++
+++++
+++++
+++++
1 oz
—
—
—
—
—
—
4 oz
2 to 2¾ oz
2.5 to 4.0 oz
2 to 4 oz
5 to 6 oz
2 oz
34.5 oz
12
12
12
12
12
12
12
7
14
7
30
28
14
14
Threshold level for second brood white apple
leafhopper nymphs (which occur in late July
to early August) is one nymph per leaf.
Treatment will eliminate the need to treat for
adults immediately before harvest.
Generally, low rates of insecticides will
control leafhoppers.
Control brown
marmorated stink bug.
Insecticides
Actara
Bifenthrin 2EC
Danitol 2.4EC
Warrior 1CS
+++
+++
+++
+++
4.5 to 5.5 oz
2 to 2.4 fl oz
16 to 21.6 fl oz
2.56 to 5.2 fl oz
12
12
24
24
35
7
14
21
Brown marmorated stink bug is a new pest,
and there is an incomplete knowledge base
on the efficacy of various insecticides.
Insecticides recommended in 2011 are based
on their efficacy against native stink bugs.
Check with your extension office for updated
information as the 2011 season progresses.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
27
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
interval
(hours)
Preharv.
interval
(days) Comments
Control spotted
tentiform leafminer.
Insecticides
Lannate 90SP
Delegate WG
Vydate 2L
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Clutch 50WDG
++++
+++++
++++
+++
++++
++++
++++
++++
¼ lb
—
1 to 2 pt
2 oz
—
—
—
—
1 lb
4.5 to 7 oz
4 to 8 pt
8 oz
4.5 oz
2.5 oz
2 to 4 oz
3 oz
72
4
48
12
12
12
12
12
14
7
14
7
14
7
28
14
A threshold level of two mines per leaf for
second generation larvae (June to July)
should be used to dictate the need for
STLM control. Control of third generation
larvae (August) may be necessary on late-maturing
cultivars if populations exceed 4
mines per leaf. Many orchards have high
levels of parasites by this time, which
usually precludes the need for insecticides.
Insecticides are more effective against sap-feeding
mines than tissue feeders.
Control green apple
and spirea aphids.
Insecticides
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Clutch 50WD
+++++
+++++
+++++
+++++
+++++
1 to 2 oz
—
—
—
—
4 to 8 oz
4.5 oz
2.5 to 4.0 oz
2 to 4 oz
2 oz
12
12
12
12
12
7
35
7
28
14
Threshold level for green apple aphid is
50% infested terminals. Control is most
important on young trees and in dwarf
plantings. On mature trees, a higher
threshold is tolerable.
Control Comstock
mealybug.
Insecticides
Diazinon 50WP
Actara 25WDG
Assail 30SG
Movento 2SC
+++++
+++
+++++
+++
1 lb
—
—
—
4 lb
4.5 oz
4 to 8 oz
6 to 9 fl oz
96
12
12
24
21
35
7
7
Applications should be made near the
second or third cover spray. Comstock
mealybug is an unpredictable pest, and
orchards with a history of problems are
most susceptible.
Control woolly apple
aphid
Insecticides
Provado 1.6F
Movento 2SC
Diazinon 50WP
++
++
+++++
—
—
1 lb
6 to 8 fl oz
6 to 9 fl oz
4 lbs
12
12
24
7
7
21
Woolly apple aphid control can be difficult
if insecticides are applied after populations
reach large densities. Use a threshold of
10% infested shoots.
An adjuvant must be used with Movento.
Control redbanded
leafroller.
Insecticides
See insecticides for tufted
apple bud moth.
Redbanded leafroller is a sporadic problem.
If damage is done, it is usually by the last
generation, which lays eggs from mid
August to mid September.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
28
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control lesser apple
worm.
Insecticides
See insecticides for codling
moth.
Lesser apple worm is a sporadic pest of
importance in isolated areas. If damage
occurs, it is usually by the third generation,
which occurs in August.
Control dogwood
borer.
Insecticides
Lorsban 50W,
4E
++++
+++++
3 lb
1.5 qt
—
—
96
96
28
28
Apply insecticides with a handgun sprayer
to the trunk, especially to burr knots and
graft unions. Moths can lay eggs from mid
May through September, so treatment
before July is optimal. Lorsban should be
applied with a handgun sprayer from no
more than 4 ft or with a shielded sprayer to
prevent drift onto foliage or fruit.
Control European red
mite and two-spotted
spider mite.
Monitor trees for mite
activity.
*****
See IPM practices for European red
mite. European red mite and two-spotted
spider mite threshold levels before July are
7 mites per leaf (85% infested leaves) and
10 mites per leaf (90% infested leaves)
during July and August. If populations are
near threshold level and Stethorus punctum
is present, recheck in 3 to 4 days to
determine if biological control reduces
mite populations. In orchards with
Alternaria blotch, a threshold of 1 mite/leaf
(50% infested leaves) should be used to
minimize stress to trees.
Miticides
Acramite 50WS
Nexter 75WP
Portal 0.4EC
Apollo SC
Savey 50DF
Zeal 72WDG
Envidor 2SC
Vendex 50W
wettable sulfur
summer oil
+++++
++++
+++++
++++
++++
+++++
+++++
++++
+
++
—
—
—
—
—
—
—
¼ lb
1½ to 3½ lb
½ to 1 gal
¾ to 1 lb
4.4 oz
1 to 2 pt
4.0 oz
3.0 oz
2 to 3 oz
16 to 18 oz
2 lb
5 to 15 lb
½ to 1% soln.
12
12
12
12
12
12
12
48
12
12
7
25
14
45
28
28
14
14
7
0
If Apollo or Savey were used at petal fall,
do not reapply at this time. Do not expect
complete control with a single application
of oil or sulfur. These materials must be
applied multiple times for best results.
Applying a highly refined summer oil
when mite populations are beginning to
increase (first and second covers) will help
suppress European red mite infestations.
Do not apply captan 2 weeks before or
after an oil spray.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
29
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Weed Management
Spot-treat with
herbicide to control
difficult-to-manage
perennial weeds.
glyphosate *****
++++
See Weed Response to
Herbicide table
(pages 51 to 53).
4 1 Apple trees are especially sensitive to
glyphosate applied in late summer and fall.
Avoid contacting tree bark and especially
foliage.
Bermudagrass control. Poast *****
++++
1.5 pt
followed by
1 pt
12 14 Apply when bermudagrass has 4 to 6-
inches of new growth in spring. Follow
with a second application when
bermudagrass has 4 inches of regrowth.
POSTHARVEST
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Plant Growth Regulators
Control fruit storage
scald.
DPA
++++
2½ pt per one gal of
water as a dip or spray
to harvested fruit.
See Growth-Regulating Chemicals section
(page 67) for complete details.
To maintain apple flesh
firmness, fruit acidity and
minimize scald.
SmartFresh
++++
See Growth-Regulating Chemicals section
(page 67) for complete details.
Weed Management
Apply POST or PRE +
POST herbicide.
See herbicide guide.
***
See herbicide guide.
See product labels.
In areas where heavy populations of winter
annual weeds are present, apply herbicide as
part of vole management program. Application
of a fall preemergence herbicide will delay the
spring herbicide application to early May or
later.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
30
Tree Row Volume (TRV):
A Model for Determining Spray Volume
The TRV model is a simple and objective method of determining (1) the volume of tree
canopy on an acre of orchard, regardless of row spacing, tree size, age, or other factors; and
(2) the dilute application water rate and chemical quantity for dilute (1X) applications or
concentrate chemical load per acre needed to effectively spray each particular orchard,
regardless of pruning and tree canopy density.
The TRV concept rests on these assumptions: Each row of trees is a wall of foliage, and
water and chemical loads required can be related to the volume and density of foliage
within that wall. Only three measurements must be made: (1) The distance between rows of
trees; (2) the maximum tree height to be sprayed; and (3) the spread from drip line to drip
line, which must be accurately measured to at least the nearest foot. In addition, an
assessment of tree density is needed to calculate the TRV of an orchard.
Using these measurements, the TRV of any orchard can be calculated using the following
formula:
Step 1:
Step 2: Feet of row/acre (from Step 1) X tree height (ft) X cross-limb spread (ft) = cu ft of
foliage/acre.
Steps 1 and 2 determine the volume of foliage canopy per acre in the orchard.
Step 3: Select one of the numbers from Table 1 that best indicates the canopy density of
each separate orchard or block.
The cubic feet of foliage volume from Step 2 and the tree density established in Step 3 are
used to calculate the water volume required per acre for a dilute spray application to
provide maximum chemical load with a dilute airblast sprayer (applied to runoff).
Step 4:
cu ft of
foliage/acre canopy density
(from Step 2) X (from Step 3) =
1,000 cu ft
gallons of dilute solution
to be applied per acre for
a maximum application
Example
Consider an orchard that has rows spaced 25 feet apart, trees 20 feet high, a spread of 17 feet
from drip line to drip line, and a tree density of 0.85.
Step 1:
Step 2: 1,742.4 ft X 20 ft X 17 ft = 592,416 cu ft
Step 3: Density has been given as 0.85 gal/1,000 cu ft
Step 4:
However, general pesticide applications are not applied to runoff. Using 70 percent (0.70) of
the “to runoff” calculated rate reduces the dilute application just to the point of drip, or what
we call “pesticide dilute.” Table 2 gives the adjustments to the “TRV calculated water rates
for dilute to runoff” water application rate for various chemicals used and types of spray
applications. The 503.5 gallons per acre in the example above is used to illustrate the
adjustments in Table 2.
Table 1. Canopy density adjustments in tree row volume (TRV) model.
0.70 gal/1,000 cu ft
Trees extremely open, light visible through entire tree, less
than 15 scaffold limbs per tree or young tree.
0.75 gal/1,000 cu ft
Trees very open, 18 to 21 scaffolds per tree, light penetration
throughout tree, healthy spurs within tree canopy.
0.80 gal/1,000 cu ft
Trees well pruned, adequate light in trees for healthy spurs
throughout trunk and scaffold limbs, many holes or openings
in foliage where light is visible through tree.
0.85 gal/1,000 cu ft
Trees moderately well pruned, reasonable spur population
within canopy, tree thick enough that light is not visible
through bottom ⅔ of tree.
0.90 gal/1,000 cu ft
Trees pruned minimally, spurs inside canopy are weak due to
limited light, very few openings where light is visible
throughout the tree.
0.95 gal/1,000 cu ft
Little or no pruning, spurs dead or very weak in canopy, very
little light visible throughout the tree.
1.00 gal/1,000 cu ft
Tree unpruned, extremely thick, no light visible anywhere
through tree canopy, trees more than 20 ft high.
43,560 sq ft/acre
distance between rows (ft) = feet of row/acre
43,560 ft2
25 ft = 1,742.4 ft
592,416 cu ft X 0.85 gal
1,000 cu ft = 503.5 gal/acre will apply a dilute
application to runoff.
31
Table 2. Adjustments in tree row volume (TRV) calculated water rates per acre for
various chemicals and types of spray applications.
Type of spray and chemical
application
% of the calculated TRV
dilute to runoff gallonage to
be used for a dilute
application
Actual gallons/acre
to be used in
previous TRV
example orchard
1Pre-petal fall dilute pesticide
application (adjusted because
of incomplete foliage
development)
56
282
Dilute pesticide application
(from petal fall on and all
other applications not
specifically mentioned)
70
352
ProVide and Promalin
(as a fine mist)
40 to 50
201 to 252
Spur Red Delicious thinners
and dormant oil applications
100
504
Thinners for other varieties
70 to 90
352 to 453
Vegetative growth inhibitor
80 to 90
403 to 453
Preharvest Ethrel plus stop-drop
spray
100 to 120
504 to 605
1To use this reduced gallonage requires accurate nozzling to top of trees and good air displacement within
trees (i.e., reduced tractor speed).
Table 3 demonstrates how the chemical load and water volume for concentrate sprays can
be easily calculated from the TRV model.
The TRV model is accurate for dilute and concentrate chemical applications with
conventional airblast sprayers, using water volumes as low as 150 gallons per acre. Below
this gallonage, the physics of droplet size and impingement on the foliage can become a
limiting factor in obtaining effective deposition on trees. Thus, if the TRV model calculates
a water application rate of less than 150 gallons per acre, a 150 to 200 gallon rate should be
considered a minimum in a conventional airblast sprayer, or be sure you are using a
concentrate engineered sprayer (higher air speed) that will ensure adequate impingement of
the spray solution on the tree surfaces at low water volume.
Table 3. How to calculate concentrate application rates.
Concentrate
pesticide
application
(3X water
rate)1
Dilute pesticide TRV gallonage 352 gal/acre
Concentrate rate = 3X = 117 gal/acre
Concentrate
pesticide
chemical load
per acre
(2X to 4X)2
Rate of pesticide
per 100 gal X
Dilute pesticide
TRV gal/acre 2.0 X 352
100 gal
=
100
= 7.1 lbs/acre
5X or greater3
Rate of
pesticide per
100 gal X
Dilute
pesticide TRV
gal/acre X 0.8 = 2.0 X 352 X 0.8 =
100 gal 100
5.6
lbs/acre
1Assume the example orchard was to be sprayed at 3X concentration.
2Rate per 100 gal dilute. Example based on 2.0 lb pesticide/100 gal.
3This adjustment for concentrate application (5X or greater) should be made if spraying conditions are good
and trees are properly matched to the sprayer. Adequate spray coverage cannot be assumed with concentrate
application if sprays are applied during windy conditions or to thick, oversized trees.
Dwarf High-Density Orchards
Dwarf high-density orchards represent a special situation for TRV applications. Most high
density orchard TRV water application rates calculate out at well below the minimum
desirable gallonage for good droplet impingement (below 150 gallons/acre). We have
consistently found improved efficacy of pesticide application and improved time efficiency
by calibrating for double the TRV. This raises the water application rate above the minimum
desirable gallonage, and then you must drive every other row middle to reduce actual water
volume per acre of orchard back to true TRV calculated rate. Pesticides are applied on a
normal interval, alternating drive middles.
The reality of sprayer calibration and nozzling for chemical applications is that until the
proper chemical load is appropriately delivered and deposited on leaf and fruit surfaces, the
spray you apply cannot be considered an effective pesticide application.
32
IPM Practices for Selected Pests
Plum Curculio
Adults overwinter in leaf litter in and around orchards. In the spring when the daily
maximum temperature exceeds 70°F, adults emerge, mate, and lay eggs under fruit skin.
Adults generally begin to enter orchards shortly before bloom, but depending on weather
conditions, new adults can continue to enter until shortly after petal fall. An insecticide
application at petal fall is important to minimize damage when adults are present. Adults
are ¼-inch-long weevils with a curved snout; they are mottled black, gray, and brown with
two bumps on each wing cover and a white marking across the back. Eggs hatch within a
few days after being laid and feed in the fruit. The mature larva is ¼-inch long, white,
slightly curved, and legless. Damage on apples is usually observed as feeding or oviposition
scars and is cosmetic. There are two generations per year in most areas of the Southeast.
Scouting and Control: After bloom, check twice weekly for plum curculio adults or feeding
and egg-laying scars. Typically, an insecticide at petal fall is sufficient for control, but
occasionally emergence may be protracted and a second application at first cover may
further suppress damage.
Apple Maggot
The apple maggot usually completes one generation per season at elevations above 2,000
feet and two generations at less than 1,200 feet. However, depending upon the year, fly
activity can extend from June through September. Adult fly emergence from overwintering
pupae in the soil is unpredictable and can occur from late May to August, but the peak
emergence is usually between mid July and early August. About 7 days after emergence,
flies become sexually mature and mate, after which females deposit eggs under the skin of
apples by puncturing them with their ovipositor. After a few days a small maggot hatches
from the egg, and the maggot tunnels within the fruit. When mature, the maggot exits the
apple, drops to the ground, and burrows into the soil, where it completes development and
forms a pupa. The pupa is the overwintering stage, and it emerges as a fly the following
summer. If fly emergence is early in the season, some of their progeny emerge the same
season rather than overwinter. In addition, a small percentage of flies may not emerge until
2 to 4 years later.
Weather conditions are important in dictating the timing and length of fly emergence. Pupae
that are overwintering in lighter soils and in sunny areas emerge before those in heavier
soils and shady areas. Sufficient soil moisture is also necessary for flies to emerge from
soil-borne pupae. Drought delays or prevents many flies from emerging. Also, abandoned
orchards (or even a few nonsprayed trees) and wild hawthorn trees adjacent to apples are
potential sources of flies, and are a threat to commercial orchards located within a distance
of about 400 yards.
Monitoring and Control: Monitor apple maggot adults with red sticky spheres that are
baited with a fruit essence lure. Baited spheres catch two to four times as many adults as
nonbaited spheres. In orchards with no history of maggot injury, a minimum of three red
spheres should be placed on the outside row of an orchard closest to the suspected source of
flies (e.g., abandoned orchard). Hang spheres in trees with fruit, and remove the fruit
adjacent to the sphere. In orchards with a history of damage, also place traps within orchards
on the southern side of trees. When using baited spheres, apply an insecticide after catching
five flies cumulatively. Repeat an application at 14-day intervals if captures again reach 5
flies. Because the timing of emergence is difficult to predict, insecticide sprays should not be
based on population trends of the previous year.
Codling Moth
Codling moths begin to emerge and mate during April or early May, depending on location,
and complete two generations per season. Depending on location and the year, a partial or
complete third generation may occur. Eggs generally begin to hatch near the first cover
spray, and soon larvae tunnel into and feed inside fruit. The mature larvae are similar to
Oriental fruit moth larvae, being ½-inch long and pinkish-white with legs. Unlike the OFM,
codling moth larvae do not have an anal comb.
In recent years the codling moth has become a serious problem in orchards throughout the
Southeast. Factors associated with problem orchards are (1) bin piles stored near orchards
and/or (2) insecticide-resistant populations. Bins are an ideal environment for overwintering
larvae, and when they complete their development the following spring the adults disperse to
nearby orchards. Recent research suggests that orchards within 100 to 150 yards of bin piles
are particularly prone to infestation. Insecticide resistance has been detected in a number of
orchards where problems have persisted for one or two years.
Codling Moth Degree-Day Model
The codling moth degree-day model is used to predict adult emergence and egg hatch of
each of the two to three generations that occur each year. The model has been in existence
for more than 30 years, and it has worked well throughout the US. However, the model may
not be entirely accurate where insecticide-resistant populations occur or where bin piles are a
source of codling moths, because these moths emerge later than predicted by the model.
Base a decision to spray insecticides against codling moth on pheromone trapping and the
codling moth degree-day model. Use pheromone traps to determine the starting point of the
model (biofix) and to gauge the intensity of populations. The degree-day model predicts
percent of adult emergence and egg hatch for each of the two to three generations of codling
moth that annually occur in the Southeast. The model is quite accurate for the first
generation, but is less accurate for subsequent generations.
To use the model, begin to accumulate degree days when male flight begins in the spring,
which is referred to as biofix. The biofix date is determined with pheromone traps to detect
the first sustained catch of two or more moths in the spring. Traps should be placed in
orchards near the tight cluster stage of bud development, and checked one to two times per
week. Hang traps at a density of one trap per 10 acres of orchard. Traps hung in the upper
third of the canopy catch more moths than those in the lower canopy and are a preferred
location. Once biofix is determined, degree days are calculated daily. It is only necessary to
check traps once per week after biofix is determined. Use the table on page 36 to determine
the number of degree days occurring at various maximum and minimum daily temperatures.
33
First Generation: Recommendations are provided for low- and moderate-to-high population
densities. Low-density orchards are those with less than 0.5 percent of the fruit damaged the
previous year and pheromone trap catches that do not exceed 10 moths per trap per week
anytime during the first generation (to about 850 DD after biofix).
In low-density orchards, make a single insecticide application at 350 DD after biofix. In
moderate-to high-density orchards, apply two insecticide applications 14 days apart, the first
at 150 to 250 DD after biofix: 100 to 150 if using a product which depends primarily on
ovicidal activity for control (i.e., Intrepid or Rimon), and 250 if using an insecticide that
targets early stage larvae. Additional applications may be necessary if trap captures remain
high (greater than 7 moths per trap).
A second emergence of overwintering adults sometimes occurs between 500 and 800 degree
days after biofix. This is often referred to as the “B peak” and may be associated with
insecticide-resistant individuals in the population. Hence, pheromone trapping is important
throughout the flight period.
Second Generation: Recommendations are provided for extremely low, low, and moderate-to-high
population densities. Extremely low-density orchards may not require an insecticide
application (no first-generation damage is observed and pheromone trap catches remain below
one moth per trap per week between 1,000 and 2,000 DD after biofix). Low-density orchards
require one insecticide application, and recent research indicates the optimum timing is 1,400
to 1,500 DD. These orchards may have no sign of damage by first generation larvae and trap
catches between 3 to 7 moths per trap per week between 1,000 to 1,500 DD after biofix.
Moderate-to high-density orchards will have fruit damage and higher pheromone trap catches
requiring at least two insecticide applications at 14-day intervals, starting about 1,400 DD
after biofix.
Third Generation: The model should not be relied upon alone for timing insecticide
applications for the third generation, because the model becomes less accurate over time.
Exceptions to the Model: Where codling moth populations are extremely high and where
pheromone trap catches remain high between generations, additional insecticide applications
at shorter intervals may be necessary. This often occurs in orchards adjacent to an abandoned
orchard or where bins are placed near an orchard.
Relationship between degree-day accumulations from biofix and percentages of
co dling moth adult emergence and egg hatch.
Cumulative
Degree Days
% Adult
Emergence
% Egg
Hatch
Cumulative
Degree Days
% Adult
Emergence
% Egg
Hatch
0 (biofix)
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1,000
1,050
1,100
1,150
1,200
1,250
1
5
15
27
40
52
63
72
80
87
91
95
97
98
99
99
100
0
1
2
5
8
13
18
26
35
0
0
0
0
0
3
9
18
30
42
54
64
73
81
87
92
95
97
98
99
100
0
1
2
3
6
1,300
1,350
1,400
1,450
1,500
1,550
1,600
1,650
1,700
1,750
1,800
1,850
1,900
1,950
2,000
2,050
2,100
2,150
2,200
2,250
2,300
2,350
2,400
2,450
2,500
2,550
43
52
60
68
77
80
85
89
92
95
97
99
0
2
4
7
10
15
20
25
31
38
45
52
59
65
10
15
21
28
36
45
63
62
69
75
81
85
89
92
95
94
99
100
3
5
8
12
16
21
27
31
Oriental Fruit Moth
Oriental fruit moths begin to emerge and mate before apple bloom, and eggs begin to hatch at
petal fall. Variable spring temperatures cause erratic emergence and egg laying by first-generation
moths. The larvae feed on shoot tips and inside apple fruit. The mature larva is ½-
inch long, pinkish-white, and has an anal comb and legs. The only way to distinguish between
Oriental fruit moth and codling moth larvae is to use a hand lens to examine mature larvae for
the presence of an anal comb. Codling moth larvae do not have an anal comb.
Oriental Fruit Moth Degree-Day Model
Base a decision to spray insecticides against Oriental fruit moth on pheromone trap catches and
a DD model. The biofix is determined in the same manner as for the codling moth. Use
pheromone traps to determine the starting point of the model and to gauge the intensity of
populations. The degree-day model predicts adult emergence and egg hatch for the first three
34
generations of the four or five generations that occur in the Southeast. However, generations
overlap in the late season, which makes the degree-day model less useful later in the season.
The table on page 36 uses daily maximum and minimum temperatures to determine daily DDs
for Oriental fruit moth (base 45°F). Place traps in the orchards near the green-tip stage of bud
development, and check one to two times per week. Hang traps at eye level at a density of 1
trap per 10 acres of orchard. Check traps weekly after the biofix date.
First-Generation OFM: Control of the first generation is often important to prevent first-generation
damage and to reduce populations of subsequent generations. First-generation egg
laying is usually low on apple, and only one insecticide application between 400 and 500 DD
after biofix is necessary, which usually coincides with petal fall.
Second-Generation OFM: If first-generation control was successful, second-generation
populations are usually very low. Extremely low-density orchards may not require an
insecticide application (pheromone trap catches never exceed 3 moths per trap per week
between 800 to 1,600 DD after biofix). In low-density orchards (3 to 5 moths per trap per
week caught between 800 and 1,500 DD), make a single insecticide application at 1,400 DD.
Moderate- to high-density orchards will have fruit damage, higher pheromone trap catches, or
both, and may need two insecticide applications 14 days apart starting at 1,100 DD.
Third-Generation OFM: An insecticide is recommended at 2,200 DD after biofix if
pheromone trap catches exceed 5 moths per trap per week at 1,900 DD after biofix and if there
is fruit damage caused by the second generation.
Fourth-Generation OFM: Because of overlapping generations late in the season, it is difficult
to predict when egg hatch of the fourth generation begins. However, continuous egg laying
can occur from August through October, and pheromone traps are the best method to
determine the potential for late-season damage. Apply an insecticide within 7 to 10 days of a
pheromone trap threshold of 7 moths per trap per week.
Tufted Apple Bud Moth
The tufted apple bud moth (TABM) is the most common leafroller occurring on apple in the
Southeast. TABM completes two generations per year, with egg laying occurring during June
(first generation) and August and September (second generation). Larvae feed on leaves and
fruit, with fruit damage usually observed as surface feeding. However, second-generation
larvae often feed within the calyx end of fruit. Unless an individual orchard has a history of
damage by this insect, it is doubtful that special precautions need to be taken. Timing is
critical to the successful management of this pest. Depending on the type of insecticide used
and the intensity of the TABM population, one or two applications during each of the two
generations may be necessary. Maintain a clean orchard floor, particularly in the early spring
before bloom, to minimize TABM populations by removing the food source for overwintering
larvae. New apple sucker growth and broadleaf weeds are important food sources in the
spring. In recent years TABM populations have been reduced to very low numbers because of
new, more effective insecticides used in many orchards.
Tufted Apple Bud Moth Degree-Day Model
A TABM degree-day model similar to that of the Oriental fruit moth and codling moth has
been tested and modified for populations in the Southeast. For calculating degree days from
maximum and minimum daily temperatures, use the Oriental fruit moth table on page 35
(45°F). Place TABM pheromone traps at the tight cluster to pink stage of bud development at a
density of 1 trap per 20 acres of orchard. Biofix is the first date on which a sustained catch
occurs and may vary from 2 to 15 moths per trap over a one-week period. The cumulative
number of degree days from the point of biofix is used to predict percentage of egg hatch and
to time insecticide applications against the first generation.
First-Generation Recommendation: When population densities are sufficiently high or if a
short residual insecticide is used, two insecticide applications per generation may be necessary;
make the first application at about 10 percent egg hatch, which occurs at about 800 DD after
biofix, and the second application 14 days later. Where populations are low or if using a long
residual insecticide (Intrepid, Delegate, Altacor, or Voliam Flexi), one application per
generation should be made anytime between 10 and 30 percent egg hatch of the first
generation, or from 800 to 1,200 DD after biofix.
Second-Generation Recommendation: Population densities of second generation TABM have
been low in recent years since the registration of highly effective new insecticides such as
Altacor, Intrepid, Delegate, and Rimon. In fact, insecticidal control of the second generation
has not been necessary in many orchards when one of these products was used against the first
generation. Not unless pheromone trap captures exceed about 15 moths per trap by 2,600 DD
after biofix (time of 10% egg hatch of the second generation) is an insecticide application
recommended. Control is most important on later maturing apples that are harvested after mid
September.
Mating Disruption
Mating disruption programs consist of emitting relatively large amounts of sex pheromone into
an orchard environment to disrupt the normal mate-location process. Mating disruption
prevents or reduces mating and the subsequent laying of fertile eggs, which effectively reduces
populations below economically damaging levels. It is effective only in blocks of 5 acres or
more. In apples, mating disruption is registered for codling moth and Oriental fruit moth.
Oriental fruit moth is much easier to control with mating disruption compared with codling
moth; use both mating disruption and insecticides against moderate to high codling moth
populations. Mating disruption will not control infestations resulting from immigrating
fertilized female moths; hence, mating disruption alone is not recommended in blocks
located adjacent to a likely source of immigrating moths (such as abandoned orchards or bin
storage areas).
Pheromone Dispensers: A number of companies market pheromone dispensers for mating
disruption, including hand-applied dispensers that emit pheromones for a relatively long period
and sprayable products that last for shorter periods and need to be reapplied. Companies are
now marketing pheromone dispensers that contain both codling moth and oriental fruit moth so
that a single dispenser type can be used for mating disruption of both insects. Dispensers vary
in the amount of pheromone they contain and the length of time during which pheromone is
35
emitted, so read the label beforehand to ensure that dispensers are used properly. Because both
codling moth and Oriental fruit moth are potential pests in the Southeast, it is highly
recommended that dual pheromone dispensers be used.
Timing of Applications: For the codling moth, place pheromone dispensers in the orchard
before adults begin to fly in the spring. First emergence of adults usually begins during late
bloom or petal fall of Delicious cultivars. Hence, dispenser application should be completed
by petal fall. Best results are obtained when dispensers are hung in the upper third of the
canopy, because this is where mating occurs.
The Oriental fruit moth begins to emerge near green tip of Delicious cultivars, so for season-long
control, dispensers should be in the orchard by this time. However, insecticides applied
at petal fall for other insects usually controls this first generation, so if using Oriental fruit
moth dispensers only, application can be delayed until just before emergence of the second- or
third-generation adults (950 and 1850 DD after biofix, respectively). If using sprayable
pheromones for mating disruption, make the initial application when hand-applied dispensers
are applied. If mating disruption is not used against this insect and pheromone trap captures
remain low during the season, a single late-season application in mid to late August will help
to suppress late-season populations.
Monitoring Insects: Monitoring codling moth and Oriental fruit moth populations is of critical
importance to measure the effectiveness of mating disruption and to determine the need for
insecticides. Pheromone traps should be used to monitor moth populations, and fruit should
also be examined at periodic intervals. When properly used, pheromone trapping can be useful
to determine the need for insecticides under mating disruption orchards. Traps should be hung
in the upper one-third of the canopy, because that is where codling moth activity is most
intense. Traps should be hung at a density of no less than one trap per five acres, and
preferably one per three acres, and checked at weekly intervals. Trap captures should be added
each week, and when the cumulative number exceeds an average of three moths per trap, an
insecticide may be necessary. Threshold levels are based on using large delta-style traps and
Trece CM L2 lures, which should be replaced at 12-week intervals.
European Red Mite Management
Several beneficial arthropods can help keep European red mite (ERM) populations below
damaging levels. The most common in the Southeast are the phytoseiid mite (Amblyseius
fallacis) and a complex of generalist predators (such as lady beetles and lacewings). However,
recent research in North Carolina suggests that neither of these predators overwinters to any
significant degree within orchards, so they must be reestablished in orchards in the spring.
Hence, practices that delay the buildup of ERM and enable predators to increase before mites
become a problem will favor biological control. The two most effective practices are applying
a delayed dormant oil spray and avoiding insecticides toxic to these predators.
Monitoring Mite Populations: Use a regular monitoring program to follow the buildup of mite
populations and to determine if and when supplemental applications of a miticide are
necessary to avoid economic damage. Monitor each contiguous block of apples weekly
beginning when adult mites first appear (which may vary from mid May to late June). Within
each block, examine 5 leaves from each of 10 trees with a visor lens or hand lens. Rather than
counting the total number of mites on each leaf, record the number of leaves infested with one
or more mites, and estimate mite density from the table below.
Determining the Need for Miticides: When mite populations reach a density of 5 to 10 mites
per leaf (80 to 90 percent infested leaves), decide whether to rely on biological control or apply
a miticide to prevent mites from increasing to damaging levels. For biological control with
Stethorus punctum to occur, the ratio should be 2.5 S. punctum to 1 ERM. For S. punctum,
count the number of adults and larvae observed during a 3-minute search around the periphery
of mite-infested trees. Count the number of A. fallacis on sample leaves with a visor lens. If the
ratio of A. fallacis to ERM is between 1 to 5 and 1 to 15, biological control is possible. If
neither predator is present at sufficient numbers, and mite populations are between 5 to 10
mites per leaf, apply a miticide.
Where Alternaria blotch is a problem on Delicious apples, biological control is usually not an
option. Alternaria blotch in the presence of mite injury can lead to premature defoliation, so
mite populations must be maintained at very low levels. If preventive control measures are not
used, miticides should be used when mites reach 1-2 mites.
Relationship between European red mite density per leaf and % infested leaves.
% Mite-Infested Leaves
(>1 mite/leaf)
Expected No.
Mites per Leaf
% Mite-Infested Leaves
(>1 mite/leaf)
Expected No.
Mites per Leaf
40
45
50
55
60
65
0.7
0.9
1.1
1.3
1.6
2.0
70
75
80
85
90
95
2.6
3.4
4.7
6.8
11.4
26.4
36
Codling moth degree days (50°F lower base, 88°F upper base) at various daily maximum
and minimum temperatures.
Max
Min
54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96
20 0 1 1 2 2 3 3 4 5 5 6 7 8 9 9 10 11 12 13 14 15 15
22 0 1 1 2 2 3 3 4 6 6 6 7 8 9 10 10 11 12 13 14 15 15
24 0 1 1 2 2 3 4 4 6 6 7 7 8 9 10 11 11 12 13 14 15 16
26 0 1 1 2 2 3 4 4 6 6 7 7 8 9 10 11 12 12 13 14 15 16
28 0 1 1 2 2 3 4 4 6 6 7 8 8 9 10 11 12 13 14 15 15 16
30 0 1 1 2 2 3 4 5 6 6 7 8 9 10 10 11 12 13 14 15 16 16
32 0 1 1 2 3 3 4 5 6 6 7 8 9 10 11 11 12 13 14 15 16 17
34 0 1 1 2 3 3 4 5 6 7 7 8 9 10 11 12 13 14 14 15 16 17
36 0 1 1 2 3 4 4 5 6 7 8 8 9 10 11 12 13 14 15 16 17 17
38 0 1 1 2 3 4 4 5 6 7 8 9 10 11 11 12 13 14 15 16 17 18
40 0 1 2 2 3 4 5 6 6 7 8 9 10 11 12 13 14 15 16 17 17 18
42 0 1 2 2 3 4 5 6 7 7 8 9 10 11 12 13 14 15 16 17 18 19
44 0 1 2 3 3 4 5 6 7 8 9 10 11 12 13 14 15 15 16 17 18 19
46 0 1 2 3 4 5 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
48 1 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 20
50 1 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
52 2 3 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
54 - 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
56 - 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
58 - - 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
60 - - - 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
62 - - - - 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
64 - - - - - 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
66 - - - - - - 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
68 - - - - - - - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
70 - - - - - - - - 18 19 20 21 22 23 24 25 26 27 28 29 30 31
72 - - - - - - - - - 20 21 22 23 24 25 26 27 28 29 30 31 32
74 - - - - - - - - - - 22 23 24 25 26 27 28 29 30 31 32 33
76 - - - - - - - - - - - 24 25 26 27 28 29 30 31 32 33 34
80 - - - - - - - - - - - - 26 27 28 29 30 31 32 33 34 35
Oriental fruit moth degree days (45°F lower base, 91°F upper base) at various daily
maximum and minimum temperatures.
Max
Min
50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96
20 1 1 2 2 3 4 4 5 6 7 8 9 9 10 12 12 13 14 15 16 17 17 18 19
22 1 1 2 2 3 4 4 6 7 7 8 9 10 11 12 12 13 14 15 16 17 18 18 19
24 1 2 2 2 4 4 5 6 7 7 8 10 10 11 12 12 14 15 15 16 18 18 19 20
26 1 2 2 3 4 5 5 6 7 7 8 10 10 11 12 13 14 15 16 16 18 18 19 20
28 1 2 3 3 4 5 5 6 7 8 9 10 10 11 13 13 14 15 16 17 18 19 20 20
30 1 2 3 3 4 5 5 6 7 8 9 10 10 12 13 13 15 16 16 17 19 19 20 21
32 1 2 3 3 4 5 6 6 8 8 9 10 11 12 13 14 15 16 17 18 19 19 20 21
34 1 2 3 3 4 6 6 7 8 8 10 11 11 12 14 14 15 17 17 18 19 20 21 21
36 1 2 3 3 5 6 6 7 8 9 10 11 11 13 14 14 16 17 18 19 19 20 21 22
38 1 2 3 4 5 6 6 7 9 9 10 11 12 13 14 15 16 17 18 19 20 21 21 22
40 1 2 3 4 5 6 6 8 9 9 10 11 12 13 15 15 16 18 18 19 20 21 22 23
42 1 3 4 4 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
44 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
46 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
48 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
50 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
52 - 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
54 - - 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
56 - - - 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
58 - - - - 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
60 - - - - - 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
62 - - - - - - 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
64 - - - - - - - 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
66 - - - - - - - - 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 35
68 - - - - - - - - - 23 24 25 26 27 28 29 30 31 32 33 34 35 36 36
70 - - - - - - - - - - 25 26 27 28 29 30 31 32 33 34 35 36 37 37
72 - - - - - - - - - - - 27 28 29 30 31 32 33 34 35 36 37 38 38
74 - - - - - - - - - - - - 29 30 31 32 33 34 35 36 37 38 39 39
78 - - - - - - - - - - - - - 31 32 33 34 35 36 37 38 39 40 40
80 - - - - - - - - - - - - - - 33 34 35 36 37 38 39 40 41 41
37
Pesticide Resistance Management
General Considerations
Pesticide resistance is a shift in the genetics of a pest population that allows individuals
within a previously susceptible population to survive. Resistant pest populations have
inherited traits that reduce their susceptibility to individual pesticides or groups of
pesticides. Resistance develops in all agricultural pest groups—insects, mites, fungi,
bacteria, nematodes, and weeds. Pesticide-resistant individuals are initially quite rare in
pest populations. However, when a new pesticide is first used, a very low number of
individual pests never previously exposed to the novel chemistry can be expected to be
resistant. The frequency of resistant genes to novel chemistries varies tremendously, but
history makes it clear that resistant individuals should be expected in all pest groups. By
the nature of the process, resistance most often develops to pesticides that are initially
very effective and frequently used.
Pesticide resistance management is an effort to slow or prevent the development of
resistance. It relies on pest management and pesticide-use strategies to prolong the
effective life of pesticides. Resistance management is difficult, especially in high-value
crops such as fruit, where high quality standards and limited numbers of registered
pesticides make the task more challenging.
Managing resistance requires an understanding of the factors that influence its
development. Selection is the process of pesticide-induced selection for resistance.
With regular pesticide use, those rare individuals that are naturally resistant survive and
reproduce more successfully than their susceptible peers. Resistance frequency refers
to the proportion of a pest population that is resistant. Cross resistance refers to a type
of resistance in which a pest population develops resistance to more than one pesticide
within a chemical family (such as organophosphate insecticides or EBDC fungicides).
Multiple resistance involves multiple, independent resistance mechanisms, which often
lead to resistance to chemicals from different families (organophosphate and carbamate
insecticides, dodine and DMI fungicides). Resistance stability is a key factor in
managing resistance. Stability is an estimate of how well resistance persists in a pest
population once the pesticide is no longer used. The rate of reversion to a susceptible
state varies enormously. But when pesticide use ceases, selective pressure for resistance
is removed, and over time resistance will often be reduced. Resistance stability
estimates may allow limited use of resistance-prone compounds.
It is important to emphasize that control failures do not confirm resistance. Other factors
(poor timing, sprayer calibration or coverage, wash-off, high pH in spray tank water,
inappropriate materials, etc.) should be eliminated as causes for control failures before
resistance is seriously considered. Factors influencing the development of resistance can
be grouped into biological and management categories. Biological factors include pest
reproductive rate, mobility of the pest species into and out of untreated areas, and
genetic factors such as number of resistance mechanisms, resistance frequency and
intensity, and resistance stability. Management factors that influence resistance
development include how materials are applied, how often they are used, how long they
persist in the field, treatment thresholds, and strategies for using available pesticides.
Resistance management efforts study specific pest-pesticide interactions and focus on
practical strategies that growers can implement.
Pest management is practical and works in concert with pesticide-use strategies to lessen
resistance selection by facilitating prudent, as-needed pesticide use. Pesticide-use strategies
work best when implemented as a new pesticide comes into commerce. Pesticide
manufacturers, IPM scientists, and growers have come to recognize that using resistance
management from the beginning works best. Collecting baseline susceptibilities, defining
probable resistance problems beforehand, and proposing pesticide-use strategies to forestall
resistance development are the province of manufacturers and IPM scientists. Biologically
and economically sound resistance management plans offered pre-sale give growers the
best hope for managing resistance. Pesticide-use strategies are often grouped as follows: (1)
management by moderation, (2) rotation and mixtures, and (3) saturation.
Moderation means limiting the use of a pesticide. Moderation is employed in concert with
IPM practices, such as using treatment thresholds, spraying only specific pest generations
or growth stages, maintaining unsprayed wild host reservoirs to act as refuges for
genetically susceptible individuals, using pesticides with shorter residual or lower toxicity
to important beneficial populations, etc. Moderation should be used to the fullest extent that
will provide commercially acceptable control.
Rotation, and in some cases mixtures, are the bulwarks of pesticide-use strategies because
an individual pest is less likely to be resistant to two or more differing classes of toxins. In
theory, most individual pests resistant to one pesticide will be killed when exposed to a
different class of toxin. Rotations depend on having effective, labeled materials with
different modes of action. Material cost is a key practical consideration that favors rotation.
Mixtures of fungicides have been used successfully to combat disease resistance, although
cost lessens the attractiveness of this approach. Mixtures of insecticides and miticides have
typically performed poorly. Rotation is seen as the desired approach for insecticides,
miticides, and some fungicides.
Saturation, the use of higher pesticide rates to control resistant individuals, is the least
attractive resistance management approach, although it has been used to manage resistance
to DMI fungicides. Saturation is generally a last resort when there are no other effective,
labeled alternatives. In this scenario, higher rates will often provide control for a time,
although at greater cost. Synergists, chemicals that increase the toxicity of pesticides, have
sometimes been effective in boosting the efficacy of resistance-prone pesticides. As with
simple rate increases, saturation with synergists typically provides only short-term benefits.
Insecticide Resistance Management Strategies
In the southeastern United States, the tufted apple bud moth, codling moth, rosy apple aphid,
and European red mite have developed resistance to one or more pesticides. Currently,
codling moth resistance is most important, but good resistance management strategies are
required to prevent other pests from developing resistance.
Codling Moth
Insecticide-resistant codling moth populations are becoming more prevelant throughout the
Southeast. Resistance to one or more registered insecticides, including Guthion, Intrepid,
Rimon, and Assail, has been detected in a number of orchards in Georgia and North
Carolina. In situations where codling moth resistance occurs, populations usually increase to
large numbers, and frequent insecticide applications at short intervals (7 to 10 days) are
38
necessary at critical times (between 400 and 800 DD after biofix) to prevent damage.
However, such intense insecticide use may lead to higher levels of resistance, so
alternative management strategies should be used in conjunction with insecticides. Using
mating disruption is strongly encouraged as a resistance management tactic, as this will
help reduce population densities more quickly than insecticides alone and, subsequently,
the need for insecticide applications. After two to three years of continuous mating
disruption, codling moth population densities can be reduced so that only one or two total
insecticide applications are needed for season-long control. In addition, make an attempt
to avoid using more than two insecticide applications against a single codling moth
generation by incorporating codling moth virus (Cyd-X or Carpovirusine) applications
into the spray program after two applications have been made. When choosing
insecticides, rotate insecticides with different modes of action against each generation.
For example, make two applications of the same insecticide against the first generation,
but use an insecticide with a different mode of action against the second generation.
Rosy Apple Aphid
The rosy apple aphid has developed widespread resistance to Lorsban, and control
failures with Asana, Ambush, and Diazinon have become more common in recent years.
Consequently, neonicotinoid insecticides are now most commonly used for control. It is
important to remember that all neonicotinoids (Actara, Assail, Calypso, Clutch, and
Provado) have a similar mode of action and should be considered the same material for
rotation purposes.
The two best times to control rosy apple aphid on apple are (1) tight cluster to pink or (2)
petal fall. Do not apply any insecticide with the same mode of action more than once
during this time frame, and if possible do not use the insecticide used for rosy apple aphid
control more than once during the period when the aphids may occur in apple orchards
(through the third or fourth cover spray).
European Red Mite
Avoiding unnecessary miticide applications is the most effective strategy for minimizing
the potential for resistance development. A delayed dormant oil application is highly
recommended to suppress overwintering populations of European red mite and to
improve the potential for biological control to maintain mite populations below damaging
levels. On Delicious cultivars, which are susceptible to alternaria blotch and where
preventive control or low threshold levels are recommended for control of European red
mite, there is a high potential for developing resistant populations. To reduce this
potential, in addition to a delayed dormant oil application, do not use the same miticide in
successive years.
Resistance Management Strategies for Plant Pathogens
Resistance of plant pathogens to pesticides has become widespread over the past 30 years as
site-specific (systemic) chemicals have been developed and used on many crops and against
many pathogens. The broad spectrum protectants (such as captan and mancozeb) that were
used previously had multiple sites of activity in the target pathogens, greatly reducing the
likelihood of resistance development.
Resistance has become a problem in the U.S. in only three pathogens that affect apples
during the growing season: Venturia inaequalis, cause of apple scab; Erwinia amylovora,
cause of fire blight; and Pseudomonas syringae pv. papulans, cause of blister spot.
Resistance of V. inaequalis to dodine (Syllit, initially sold as Cyprex) was first reported in
New York in 1969. It has subsequently been reported in several states in the Northeast and
Midwest but has not been found in orchards in the Southeast. Resistance of V. inaequalis to
the benzimidazole fungicides (benomyl and thiophanate-methyl) was reported shortly after
their introduction in 1971 and became widespread in the eastern U.S., including the
Southeast, in the mid-1970s. As a consequence they are no longer recommended for apple
scab control in the Southeast. The ergosterol biosynthesis inhibiting fungicides (EBI) were
first introduced in the late 1980s, and reduced sensitivity of V. inaequalis has been reported
or suspected in a number of orchards in the Northeast and Midwest, but is not widespread.
Some growers in NC have also had problems controlling scab with EBI fungicides,
suggesting that resistance may be a problem here as well. Resistance of the fire blight
bacterium, E. amylovora, to streptomycin (Agri-mycin 17, Streptrol) is widespread in several
states but has not been reported in the Southeast. Resistance of P. syringae pv. papulans has
been confirmed in an orchard in Tennessee.
To avoid resistance development, minimize the use of fungicides and bactericides in which
resistance is likely to develop. Additionally, combine site-specific fungicides with
protectant fungicides that have broad spectrum activity. Limit dodine applications to two to
three per year. In areas where dodine resistance first became a problem, it was often used
10 to 12 times throughout the growing season. Similarly, limit streptomycin use for fire
blight control to two to four times a year. Make applications only during times favorable for
infection. These periods are characterized by open blossoms, dew or rainfall greater than
0.01 inch, an average daily temperature of 60°F or greater, and the accumulation of at least
198 degree-hours greater than 65°F since the first blossoms opened. Use the ergosterol
biosynthesis inhibiting fungicides only in combination with broad spectrum protectants,
such as captan or EBDC fungicides. Avoid post-symptom applications of site-specific
fungicides, such as dodine and the EBI fungicides, because this sets up an ideal situation for
selection of resistant strains. Good orchard sanitation practices to maintain pathogen
populations at low levels are also an important component of a resistance management
program.
39
Managing Weeds and Preventing the Development of Herbicide
Resistance
Although weed resistance to herbicides is not discussed as often as resistance in insects
and pathogens, cases of weed resistance to herbicides do exist. For example, pigweed
and goosegrass are resistant to dinitroanaline herbicides (Prowl and Surflan).
Johnsongrass is resistant to carboxylase herbicides (Fusilade DX), and horseweed and
pigweed biotypes have developed resistance to glyphosate. Resistance may not be
detected for several years because these resistant weeds produce seed, and then
subsequent generations must establish. Two factors that contribute to the development
of herbicide-resistant weeds are applying herbicides multiple times during the year and
using herbicides that have the same mechanism of control for several consecutive
growing seasons.
Because apples are a perennial crop and have limited herbicide options, techniques like
crop rotation and mechanical cultivation to prevent resistance in annual crops are not
feasible. However, some of the following strategies can help prevent resistance from
developing:
1. Use herbicides ONLY when necessary.
2. Rotate herbicides with different modes of action. For example, do not use simazine
(Princep, Simazine) continuously. Consider other preemergence broadleaf
herbicides. Also avoid making more than two applications of the same herbicide in
the same year.
3. Scout orchards regularly to identify weeds. Respond quickly to changes in weed
population by controlling weeds before they spread through the entire orchard.
4. Use nonselective postemergence herbicides in your weed management program.
Effect of pH on Pesticide Activity
Although the pH of spray water does not directly affect resistance development, it can
affect the activity of some pesticides. The label on dimethoate, phosmet, malathion,
azinphosmethyl, formetanate, ethephon, NAA, and possibly others warns of this effect.
When these materials, except NAA, are exposed to a pH above 7.5, they undergo
hydrolysis and break down to products that are either less effective or not effective.
Excessively acidic conditions may limit uptake of NAA and, therefore, its effectiveness.
The actual rate of breakdown depends on solubility and temperature and the total quantity
broken down during a given period. For example, captan is hydrolyzed very quickly at
alkaline pHs, but because it is very insoluble, the impact of pH is negligible unless captan
is allowed to stand for a week or more. This is also true for chlorothalonil. Hydrolysis
increases with increased temperature. If the time in the spray tank is limited by applying
pesticides immediately, then the quantitative amount broken down is limited.
Additives to the spray tank can also be a factor. Calcium chloride, especially when
concentrated in the tank and applied in a low volume spray, can increase the pH. The
greater the concentration, the greater the alkalinity. The manufacturing process for
calcium chloride leaves residues of free lime (calcium hydroxide). The greater the purity
of the calcium chloride, the lower the content of calcium hydroxide and the lower the
effect on pH.
The water source can be a factor. Although most wells, streams, and rivers in the
southeastern growing region are mildly acidic (6.7 plus or minus 0.2) there are exceptions;
therefore, check pH a few times before regular use. Ponds are more likely to be alkaline,
especially those high in algae and other organisms. These ponds undergo diurnal pH
changes as result of dissolved carbon dioxide. Levels greater than 10 have been observed.
Alkalinity contributed by CO2 is weakly buffered and readily changed by acidifying
agents.
Although not pH-related, some pesticides can be affected by other contaminants in the
water. For example, fenbuconazole, not labeled on apples, is greatly reduced in
effectiveness by suspended particulates. Still other compounds like 2,4-D and
azoxystrobilurin can be very difficult to wash out of the tank and can have a deleterious
effect on apples at very low concentrations.
40
Orchard Floor Management
The best strategy for managing the orchard floor is to use a noncompetitive grass alley
with a vegetation-free strip in the tree row. The vegetation-free strip can be established
and maintained with herbicides as described in this section. The permanent grass sod
between the tree rows will minimize soil erosion, increase soil aeration and
permeability, and support equipment movement through the orchard during wet
weather. The vegetation-free strip eliminates competition for water and nutrients,
minimizes tree damage or loss from voles during the dormant season, and provides
some radiant heat from the soil surface should a spring frost or freeze occur. Herbicides
are directed at the soil and weeds underneath the tree.
The vegetation-free strip method is superior to all other orchard floor management
options. Vegetation under the tree competes for nutrients and water, resulting in reduced
growth, yield, and size of fruit. Another option is the use of organic mulches in the tree
row. Examples of mulching materials include straw, wood chips, and grass residue from
mowing. These mulches will suppress weed emergence, but weed removal by some
means will still be necessary. Mulches can improve the water-holding capacity of some
soils. However, there are several concerns regarding the use of organic mulches. The
most significant problem is that mulches create an ideal habitat for voles. Also,
additional nitrogen may be needed to support the microorganisms that drive
decomposition of organic mulches. In poorly drained or waterlogged soils, organic
mulches increase the likelihood of phytophthora root rot. Mulches can be expensive and
difficult to obtain. Synthetic mulches made from polyethylene, polypropylene, or
polyester can be placed in the tree row around the base of the trunk or as a narrow strip
down the row. Some newer synthetics allow water and air to pass through the mulch.
Herbicide Considerations
To ensure proper herbicide use, always read the manufacturer’s label before application.
All statements on the manufacturer’s label take precedence over any recommendations
in this publication.
It is important that herbicide application equipment be properly calibrated to ensure that
herbicides are applied at the correct rate. For questions about calibrating your sprayer,
contact your county’s Cooperative Extension agent.
Remember that herbicides are applied as a directed spray along each side of the tree
row. Flat fan nozzles are most widely used for applying herbicides. They provide
excellent spray coverage of weeds and come in several sizes with capabilities to apply a
range of spray volumes. Some manufacturers make flat fan nozzles that minimize spray
drift, allowing low-pressure spraying. Investing in such spray nozzles decreases the
likelihood of off-target herbicide movement.
It is advisable to apply white latex paint to the bottom 2 to 3 feet of the tree trunk of
newly planted trees before applying herbicides. Painting the tree trunks reduces the
potential for winter as well as herbicide injury, especially from postemergence
herbicides. Dip a car wash mitt (wear rubber gloves underneath the mitt) in paint and
rub up and down the tree trunk until it is completely painted.
Several herbicides are registered for use in apple orchards. Some are preemergence
herbicides that control weeds that have not emerged, and others are postemergence
herbicides that control emerged weeds. Preemergence herbicides control germinating weed
seeds but usually do not give acceptable control of emerged weeds. Rainfall is needed to
properly activate preemergence herbicides. Rainfall within 7 to 14 days after application
activates most herbicides; however, best control occurs when water (rain or irrigation) is
added within a few days of application. The desired amount of time for rainfall after
application varies by herbicide. Refer to the manufacturer’s label for specific information.
Postemergence herbicides are most effective when applied to actively growing weeds.
Weeds under stress from drought or mowing may not be adequately controlled by
postemergence herbicides. If weeds are stressed from drought, delay herbicide application
until after adequate rainfall when weeds are no longer wilted. If weeds have been mowed,
wait several days to allow regrowth before applying herbicides. Symptoms of herbicide
activity may not be noticeable for up to 14 days after application of glyphosate,
sethoxydim, clethodim, or fluazifop (Roundup, Poast, Select, or Fusilade DX, respectively).
Effects of glufosinate, paraquat, fluroxypyr, and 2,4-D (Rely, Gramoxone Max, Starane
Ultra, and Orchard Master, respectively) are noticeable in 1 to 3 days. Some postemergence
herbicides require the addition of a surfactant or crop oil to improve herbicide activity.
Remember, surfactants and crop oil differ from one another and may not be
interchangeable.
Herbicide Application Timing
The goal of an effective weed management program is to eliminate weed competition the
first 6 to 8 weeks after bud swell and keep the area under the trees weed-free through
harvest. Timing of preemergence (PRE) herbicide application is important in accomplishing
this goal. It has been typical to make a single PRE herbicide application in the spring
followed by postemergence (POST) herbicide applications in the summer as needed.
However, it can be difficult to spray underneath limbs loaded with fruit in mid and late
summer. With appropriate PRE herbicide timing, POST herbicide applications in mid and
late summer can be avoided. Listed below are several PRE herbicide timing options.
1. Fall/Spring Split. One approach is to apply a PRE herbicide with a nonselective
burndown herbicide (glyphosate or paraquat) in the fall after harvest (November). The fall
application will generally provide PRE control into the early summer. When fall PRE
treatment breaks and emerging weeds get 2 to 3 inches tall, another PRE herbicide
application with a burndown herbicide should be applied. Fall herbicide application may be
helpful in managing voles. In areas where erosion is a concern, this option may not be
acceptable.
2. Delayed Preemergence. This approach requires a burndown herbicide application in
March. The burndown herbicide eliminates winter annual weeds until summer annual
weeds emerge in early to mid May. Once summer annual weeds get 2 to 3 inches, apply a
burndown with a PRE herbicide.
3. Spring/Summer Split. (Due to changes in label, this option is available for non-bearing
orchards only.) The registration of Chateau allows for a spring/summer split application
time. However, Chateau is the only herbicide with label flexibility to allow this sequential
application program. Chateau at 6 to 8 ounces per acre with a nonselective postemergence
herbicide can be applied in mid March. This application will last through May and into
June. In June when control from the initial application begins to fail, an additional
application of Chateau at 6 to 8 ounces per acre with either paraquat or Rely for
nonselective postemergence weed control should be applied. The Sinbar label for non-bearing
orchards allows the same use pattern as well.
41
Postemergence herbicides may b

2011 Integrated Orchard Management Guide
for Commercial Apples in the Southeast
Alabama Cooperative
Extension System
Auburn University
University of Arkansas
Division of Agriculture
Cooperative Extension Service
University of Arkansas
Clemson Cooperative
Extension Service
Clemson University
University of Georgia Cooperative
Extension Service
University of Georgia
North Carolina Cooperative
Extension Service
North Carolina State University
University of Tennessee
Agricultural Extension Service
University of Tennessee
Poison Control Centers and Emergency Facilities
PESTICIDE POISONING B Symptoms of pesticide poisoning may include
headache, blurred vision, weakness, nausea, cramps, diarrhea, and chest discomfort.
If any of these symptoms occur during or after mixing or applying pesticides or if an
unintended unprotected exposure such as a spill occurs, stop work at once and take
appropriate action. If pesticide is spilled on the skin, immediately wash the area
thoroughly with large amounts of soap and water. If pesticide is in the eye, flush the
eye for 15 minutes in running water. If pesticide is inhaled, move to open, clean air.
If pesticide is ingested, rinse out the mouth. Follow all label first aid directions. Give
CPR if indicated. Get help. Contact your physician or poison control center (listed
below or on WPS safety poster). Transport the victim to the closest medical care
facility. Take the pesticide container or the label with you, or have others search for
the label and get it to the facility.
Most pesticide poisonings are due to overexposure to organophosphate and
carbamate insecticides. Investigation indicates these are the result of misuse,
disregard for safety precautions, and lack of proper hygiene during mixing and
application. Ninety percent of occupational exposure is through the hands. Use
neoprene or butyl rubber gloves. Rubber boots prevent acute exposure from spills
and chronic exposure from accumulation of residues in materials of boots and shoes.
STATE-DESIGNATED POISON CENTERS
Dialing 1-800-222-1222 reaches the poison control center for the state from which the call is made.
ALABAMA
Alabama Poison Center
2503 Phoenix Drive
Tuscaloosa, AL 35405
800-222-1222
800-292-6678
NORTH CAROLINA
Carolinas Poison Center
Carolinas Medical Center
PO Box 32861
Charlotte, NC 28232
800-222-1222
800-848-6946
ARKANSAS
Poison and Drug Information Center
Univ. of Ark. for Medical Sciences
4301 West Markham – Slot 522
Little Rock, AR 72205
800-222-1222
800-376-4766
SOUTH CAROLINA
Palmetto Poison Center
College of Pharmacy
University of South Carolina
Columbia, SC 29208
800-222-1222
GEORGIA
Georgia Poison Center
Education Dept
80 Jesse Hill Jr. Drive, SE
Atlanta, GA 30303
800-222-1222
404-616-9287 (for the deaf)
404-616-9000 (business)
TENNESSEE
Tennessee Poison Center
1313 21st Avenue South
Nashville, TN 37232-4632
800-222-1222
2011 Integrated Orchard Management Guide for Commercial Apples in the Southeast
Table of Contents
Pest and Orchard Management Program......................................................... 2
Tree Row Volume: A Model for Determining Spray Volume...................... 30
IPM Practices for Selected Pests................................................................... 32
Pesticide Resistance Management ................................................................ 37
Effect of pH on Pesticide Activity ................................................................ 39
Orchard Floor Management.......................................................................... 40
Apple Pollination, Honey Bees, and Pesticides ............................................ 42
Soil and Plant Analysis Guidelines for Southeastern Apple Production....... 43
Fertility Management Recommendations for Apples ................................... 44
Relative Effectiveness of Fungicides............................................................ 45
Relative Effectiveness of Insecticides and Miticides.................................... 48
Toxicity of Pesticides to Beneficial Arthropods ........................................... 50
Weed Response to Preemergence Herbicides ............................................... 51
Weed Response to Postemergence Herbicides ............................................. 52
Fungicides and Bactericides ......................................................................... 54
Insecticides and Miticides............................................................................. 57
Herbicides ..................................................................................................... 63
Growth-Regulating Chemicals...................................................................... 67
Vertebrate Management................................................................................ 74
Pesticide Safety............................................................................................. 80
EPA Registration Numbers of Various Materials ......................................... 81
Recommendations for the use of agricultural chemicals are included in this
publication as a convenience to the reader. The use of brand names and any
mention or listing of chemical products or services in this publication does not
imply endorsement by the Cooperative Extension Service nor discrimination against
similar products or services not mentioned. Individuals who use agricultural
chemicals are responsible for ensuring that the intended use complies with current
regulations and conforms to the product label. Be sure to obtain current
information about usage regulations and examine a current product before
applying any chemical. For assistance, contact your local Extension Agent.
Senior Editor: Jim Walgenbach, Extension Entomologist, N.C. State University
Section Editors:
Insect Management Jim Walgenbach
Cultural/Growth Regulators Steve McArtney
Disease Management Turner Sutton
Vertebrate Management Dave Lockwood
Weed Management Wayne Mitchem
Soils and Nutrition Ron Gehl
Contributors
Alabama South Carolina
Bobby Boozer
Ed Sikora
Horticulture
Plant Pathology
Bob Bellinger
Mike Hood
Desmond Layne
Guido Schnabel
Safety
Apiculture
Horticulture
Plant Pathology
Arkansas Tennessee
Donn Johnson
Curt Rom
Elena Garcia
Entomology
Horticulture
Horticulture
Steve Bost
Edward Burgess
Frank Hale
Dave Lockwood
John Skinner
Plant Pathology
Safety
Entomology
Horticulture
Apiculture
Georgia
North Carolina
Phillip Brannen
Keith Delaplane
Paul Gulliebeau
Dan Horton
Harold Scherm
Plant Pathology
Apiculture
Safety
Entomology
Plant Pathology
Ron Gehl
Steve McArtney
Wayne Mitchem
Mike Parker
Turner Sutton
David Tarpy
Steve Toth
Jim Walgenbach
Soil Science
Horticulture
Horticulture
Horticulture
Plant Pathology
Apiculture
Safety
Entomology
2
Pest and Orchard Management Program
DORMANT
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Cultural Management
Control tree density, size,
and shape for better light
and spray penetration.
Conduct annual dormant
pruning in central leader
trees and appropriate high-density
orchards.
*****
The younger the trees, the closer to bud break
they should be pruned. Prune older and bearing
trees first; prune 1- to 2-year-old nonbearing
trees during the month before dormant bud
break.
Provide proper nutrition
for moderate tree growth
and good fruit quality.
Collect soil samples;
establish and maintain a
good lime and fertility
program. Apply late winter
fertilizer to young,
nonbearing trees, and half
rate to mature, bearing trees.
*****
See Fertility Management section (page 44) for
complete sampling, fertilizer rates, and
application methods. Apply full rate to young,
nonbearing trees to promote good tree growth.
Increase lateral bud break
and lateral shoot
development on last
year’s leader growth to
encourage scaffold limb
development.
Bag last year’s leader growth
3 to 4 weeks before
anticipated dormant bud
break.
*****
See Growth-Regulating Chemicals section
(page 67) for details.
Plant Growth Regulators
Control water sprout
regrowth near pruning
cuts and on tops of large
scaffold limbs exposed to
light by heavy dormant
pruning.
Tre-Hold A-112
See comments.
Use 10,000 ppm (10
oz/gal) as a “sponge-on”
application.
12
0
See Growth-Regulating Chemicals section
(page 67) for complete recommendation
details. The need for this practice depends on
heaviness of pruning, size of cuts, and potential
growth vigor. Effectiveness depends on
COMPLETE coverage.
Control burr knot
formation.
Gallex
**
Paint directly from can,
full strength, on burr
knots.
See Growth-Regulating Chemicals section
(page 67) for recommendation details.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
3
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Reduce inoculum of apple
scab fungus.
Shred leaves with flail
mower.
*****
May also help reduce inoculum of fungi that
cause Brooks spot, Alternaria blotch, and
Glomerella leaf spot.
Reduce inoculum of
black, white, and bitter
rot fungi.
Prune out dead wood and
mummied fruit.
*****
Pruning is extremely important to reduce the
likelihood of these diseases. Don=t stockpile
prunings near orchard. Remove and burn, or
chip with a flail mower.
Reduce inoculum of fire
blight bacteria.
Prune out cankers and old
fire blight strikes.
****
Will also reduce inoculum of black rot, white
rot, and bitter rot.
Reduce inoculum of
powdery mildew fungus.
Prune out silver-colored
terminals.
***
Particularly useful on young trees of a
susceptible cultivar.
Improve control of cedar
apple and quince rusts.
Scout orchard, adjacent
woods, or borders for red
cedar, and remove.
*****
Complete removal of red cedar in areas where
cedars are not common may eliminate need for
fungicide sprays for these diseases.
Create good conditions
for drying fruit and
foliage; improve spray
penetration.
Prune to open trees.
*****
Pruning is extremely important for good
disease control inside the canopy and in the
tops of large trees.
Weed Management
Control seedling
perennials and winter
annuals.
Apply glyphosate or
glyphosate + 2,4-D amine or
paraquat or Rely to control
emerged winter annuals.
*****
+++++
See product label.
See product label.
Apply nonselective postemergence herbicide
alone (mid March). When control from this
breaks and summer weeds are 2-3 inches tall,
apply a nonselective postemergence herbicide
with a preemergence herbicide. This will likely
be in early May, but may vary from year to
year. Delaying PRE herbicide application
results in residual control later in the summer.
Reduce dandelions.
2,4-D amine
++++
1 qt
1.0 lb
48
60 Apply at least 2 weeks before bloom to control
flowering weeds. Reduces competition with
apple blossoms to enhance bee pollination.
Control of flowering weeds will also help
control tarnished plant bug.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
4
SILVER TIP
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Control fire blight.
Bactericides
copper hydroxide
copper oxychloride sulfate
Bordeaux
++++
++++
++++
See label.
See label.
See label.
See label.
See label.
See label.
This treatment will help control fire blight in
blocks of trees of a susceptible cultivar where
fire blight has been a problem. It will not
eliminate need for streptomycin. Applications
later than 0.25- to 0.5-inch green tip may result
in injury. Most effective if applied dilute.
Control black rot.
Fungicides
Captan 50W or
4L or
80W or
80WDG
++++
++++
++++
++++
—
—
4 lb
2 qt
2.5 lb
2.5 lb
96
96
24
24
0
0
0
0
An important spray for black rot control in
Georgia. Warning: Captan will cause injury
when used with or too close to oil applications.
Fungicides
Ridomil Gold EC or WSP
++++
See label.
12
1
Aliette 80WDG or 80 WSP
++++
⅝ to 1½ lb
2 to 5 lb
12
14
Ridomil and Aliette applications are
recommended on cultivars propagated on
susceptible rootstocks planted in heavy or
poorly drained soils. Apply Ridomil in the
spring before growth starts, and repeat
application after harvest. Apply 3 to 5
applications of Aliette a year. Make first
application of Aliette after leaf emergence.
Note: Ridomil and Aliette must be applied on a
preventive basis. Treatment of trees exhibiting
symptoms will not prevent further symptom
development.
Control crown rot
(collar rot).
Phosphite fungicides
++++
See label.
Phosphite fungicides (i.e. Prophyt, Agri-Fos,
and others) are registered for crown rot control
and have activity similar to Aliette. See labels
for use instructions and precautions.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
5
GREEN TIP TO ½-INCH GREEN
Rate Per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Fungicides
Syllit 3.4FL
+++++
1.5 to 3 pt
48
7
Vangard 75WG
+++++
1.25 oz
5 oz
12
72
Vangard 75WG
+ mancozeb
80WP or
75DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
¾ oz
¾ lb
¾ lb
0.6 qt
¾ lb
3 oz
3 lb
3 lb
2.4 qt
3 lb
12
24
24
24
24
72
77
77
77
77
Vangard tends to be most active at cool
temperatures.
Scala SC
+++++
1.75 to 2.5 oz
7 to 10 oz
12
72
Scala SC
+ mancozeb
80WP or
75DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
1.25 oz
¾ lb
¾ lb
0.6 qt
¾ lb
5 oz
3 lb
3 lb
2.4 qt
3 lb
12
24
24
24
24
72
77
77
77
77
Scala SC is not compatible with captan.
Sovran 50WG
+++++
1 to 1.6 oz
4 to 6.4 oz
12
30
Flint 50WG
+++++
—
2 to 2.5 oz
12
14
Control scab.
See discussion in
Fungicides and
Bactericides (page 54)
for information on
postinfection control
program.
Pristine 38W
+++++
—
14.5 to 18.5
oz
12
0
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
6
GREEN TIP TO ½-INCH GREEN (continued)
Rate Per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
fenarimol 1E
+ captan 50WP or
80W or
80WDG
or
+ mancozeb
80WP or
75DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
3 to 4 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
8 to 12 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
30
0
0
77
77
77
77
myclobutanil 40W
+ captan 50W or
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80DF
+++++
+++++
+++++
+++++
+++++
1¼ to 2 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
5 to 10 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
14
0
0
77
77
77
77
Control scab (continued).
Procure 50WS
+ captan 50W
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
1 to 2 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
4 to 8 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
14
0
0
77
77
77
77
Do not use captan within 2 weeks of an oil spray.
Although resistance of the apple scab fungus to
the EBI fungicides has not been confirmed, some
growers have experienced problems in the
Southeast in controlling scab when using these
fungicides. Growers who have had this problem
should use a program that begins with two sprays
of Syllit, Vangard, or Scala, followed by two
sprays of Flint or Sovran. The fifth spray, which
should occur around petal fall, can include an
EBI fungicide, but it needs to be combined with a
full rate of captan or captan + mancozeb or
metiram to ensure scab control. An EBI fungicide
at this time will help control powdery mildew,
especially on mildew-susceptible varieties, and
cedar apple and quince rust if captan is used
alone.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
7
Rate Per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
Control scab (continued).
Indar 75WSP
+ captan 50W
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
0.67 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
2.67 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
14
14
14
77
77
77
77
Tebuzole 45DF
+ captan 50W
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
+++++
1 to 2 oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
2 to 8 oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
5
96
24
24
24
24
24
24
75
14
14
14
77
77
77
77
Topguard 1.04SC
+ captan 50W
80W or
80WDG
or
+ mancozeb
80W or
75DF or
F4
or
+ Polyram 80W
+++++
+++++
+++++
+++++
+++++
3.2 fl oz
¾ lb
0.47 lb
0.47 lb
¾ lb
¾ lb
0.6 qt
¾ lb
13.0 fl oz
3 lb
1.88 lb
1.88 lb
3 lb
3 lb
2.4 qt
3 lb
96
24
24
24
24
24
24
14
14
14
77
77
77
77
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
8
GREEN TIP TO ½-INCH GREEN (continued)
Rate Per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
Control scab (continued).
Inspire Super MP
+ Vangard WG
+++++
1.0 fl oz
1.0 oz
4.0 fl oz
4.0 oz
12
72
In orchards where EBI resistance is suspected
Inspire Super MP + Vangard WG should
always be combined with mancozeb or
metiram.
Adament 50W
+++++
1 to 1.25 fl oz
4 to 5 oz
5
75
Adament is a prepack combination of
tebuconazole (an EBI fungicide) +
trifolxystrobin (a QoI fungicide). Do not
make more than 4 applications per season.
Insect Management
Control scales and reduce
overwintering European
red mite and rosy apple
aphid eggs.
Insecticides
Oil
+++++
2 gal
2 to 3%
solution
12
0
Use either a superior-type or highly refined
summer oil applied dilute. If the oil
application is delayed until tight cluster to
pink, use a refined oil or reduce a superior
type to ½ to 1 gal/100 gal. Do not use captan
within 2 weeks of an oil application.
Improve scale control.
Oil +
Lorsban 4E
or
Esteem 35WP
or
Diazinon 50WP
++++
+++++
++++
2 gal
½ to 1 pt
—
1.0 lb
8 gal
2 to 4 pt
4 to 5 oz
4 lb
12
96
12
96
0
DD
45
21
An insecticide with oil may be added at this
time in orchards experiencing problems with
scales. This option is recommended in
orchards that experienced scale problems the
previous year.
Initiate Oriental Fruit
Moth (OFM) monitoring
program.
Erect pheromone traps
*****
Erect pheromone traps by green tip to detect
first emergence. See section on IPM Practices
for Selected Pests (page 32) for monitoring
information.
Mating disruption for
OFM and codling moth.
Pheromones
Isomate CM/OFM TT
CideTrak CM/OFM
CheckMate Puffer -
CM/OFM
Isomate CM/OFM Ring
+++++
+++++
+++
+++
(# dispensers)
200/acre
200/acre
1/acre
20/acre
Now is the time to begin erecting pheromone
dispensers for mating disruption.
Combination dispensers that contain both
OFM and codling moth pheromone are
recommended. Hanging of dispensers in trees
should be complete by petal fall. See section
on “Mating Disruption�� in IPM Practices for
Selected Pests (page 34).
9
TIGHT CLUSTER TO PINK
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Control scab.
Fungicides
Same as used in green-tip
spray.
If two sprays of Sovran, Pristine, or Flint were
used, switch to a nonstrobilurin fungicide.
Syllit, Scala, and Vangard are most
effectively used in the first two sprays of the
season.
Control powdery mildew.
Fungicides
myclobutanil 40W
fenarimol EC
Procure 50WS
Indar 75WSP
Tebuzole 45 DF
Topguard 1.04SC
++++
++++
++++
++++
++++
+++++
1¼ to 2 oz
3 to 4 oz
1 to 2 oz
0.67 oz
1 to 2 oz
2 to 3 oz
5 to 10 oz
8 to 12 oz
4 to 8 oz
2.67 oz
2 to 8 oz
8 to 12 oz
24
12
12
12
5
12
14
30
14
14
75
14
These are the most important sprays for the
control of powdery mildew.
Control cedar apple rust
and quince rust.
Fungicides
Same as used for
powdery mildew, or:
mancozeb 80W or
75DF or
F4
Polyram 80W
+++++
+++++
+++++
+++++
¾ lb
¾ lb
0.6 qt
¾ lb
3 lb
3 lb
2.4 qt
3 lb
24
24
24
24
77
77
77
77
Control black rot and
frogeye leafspot.
Captan 50W or
4L or
80 W or
80WDG
++++
++++
++++
++++
1½ to 2 lb
¾ to 1 qt
0.94 to 1.26 lb
0.94 to 1.26 lb
6 to 8 lb
3 to 4 qt
3.77 to 5 lb
3.77 to 5 lb
96
96
24
24
0
0
0
0
Captan alone will not control powdery
mildew or rust diseases.
Insect Management
Initiate codling moth and
leafroller monitoring
program.
Erect pheromone traps.
*****
Erect traps now because moths begin to
emerge near bloom. See section on IPM
Practices for Selected Pests (page 32) for
information on monitoring programs.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
10
TIGHT CLUSTER TO PINK (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv
Interval
(days) Comments
Control rosy apple
aphid.
Insecticides
Actara 25WDG
Assail 30SG
Calypso 4F
Diazinon 50W
Danitol 2.4EC
+++++
+++++
+++++
+++
++++
—
—
—
1 lb
2.6 to 4.3 oz
4.5 oz
2.5 to 4 oz
2 to 4 oz
4 lb
10.6 to 21.3 oz
12
12
12
24
24
35
7
30
21
14
Pink stage is the best time to control rosy
apple aphid. Caution: Rosy apple aphid
resistance to Diazinon and Danitol has been
observed in some orchards. See Rosy Apple
Aphid resistance section (page 38).
Assail may be used during bloom if sprays
are applied before or after bees are in the
orchard. Assail residues on leaves or
flowers are not toxic to bees, but avoid
spraying when bees are in the orchard.
Control plant bugs
and spotted tentiform
leafminer (STLM).
Maintain clean ground-cover.
Insecticides listed for
rosy apple aphid will aid in
plant bug and leafminer
control if plant bugs are
readily seen.
*****
In many instances, a clean groundcover
eliminates the need for insecticides to
control bugs. If there is a history of plant
bug problems, a second application at petal
fall will improve control. The need for
insecticides specifically targeting STLM at
this time is questionable because first
generation mines rarely exceed threshold
levels.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
11
BLOOM
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Cultural Management
Loosen bags on leaders to
acclimate for 2 to 3 days;
then remove bags from
leaders and spray with
Promalin or Perlan.
Leader bags must be
removed when new lateral
growth is 1” to 3” long.
*****
See Growth-Regulating Chemicals section
(page 67) for complete details.
Do leader selection and
strip whorl on dormant
headed tree leaders.
Select new shoot for
central leader and remove
competing shoots from
first four nodes below new
leader shoot.
Plant Growth Regulators
Improve fruit shape and
increase fruit weight of
Red and Golden
Delicious (can be used
only on varieties that
have dominant calyx
ends).
(BA+GA 4 + 7)
Promalin
Perlan
+++
+++
0.5 to 1.0 pt
1 to 2 pt
12
4
None
See Growth-Regulating Chemicals section
(page 67). Apply as a fine mist application
at 40 to 50% of Tree Row Volume (TRV)
water rate between king bloom opening and
full bloom.
Increase lateral bud break
and lateral shoot growth
on 1-year-old leader
growth as a tool to
encourage scaffold limb
development, especially
on those that were bagged
before bud break. Use on
nonbearing trees only.
Promalin
Perlan
+++++
+++++
250 to 500
ppm
(1 to 2 pt)/10
gal
125 to 500
ppm
(0.5 to 2 pt)/
10 gal
12
4
None
Apply to last year’s leader growth with a
handheld nozzle. See Growth-Regulating
Chemicals section (page 67).
Make one application when orchard trees
have 1 to 3 inches of new growth.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
12
BLOOM (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Control scab, rusts, and
mildew.
Fungicides
Same fungicides as
recommended in tight
cluster stage.
Avoid sprays in full bloom if possible. Do not
overextend application intervals.
Control fire blight.
Bactericides
streptomycin
4.8 to 8 oz
1½ to 2½ lb
12
50
Begin application at first bloom and continue at
3- to 4-day intervals until petal fall.
Streptomycin sprays protect only those
blossoms open at time of application. It is very
important to continue spraying through “rat-tail”
bloom, especially on susceptible varieties.
See discussion under Pesticide Resistance
Management section (page 38) for timing
sprays according to conditions favorable for
infection.
Insect Management
Protect pollinators.
Do not apply insecticides
during bloom.
*****
Keep orchard floor free of flowering weeds.
This will increase pollination activity in the
trees and lessen bee activity after apple bloom.
Disrupt mating of codling
moth.
Pheromones
Isomate CM/OFM TT
CideTrak CM/OFM
CheckMate Puffer -
CM/OFM
Isomate CM/OFM Ring
+++++
+++++
+++
+++
(# dispensers)
200/acre
200/acre
1/acre
20/acre
Do not use mating disruption in blocks of less
than 5 acres. Pheromone dispensers should be
hung before moths begin to emerge, with
hanging completed by petal fall. Also,
supplemental sprays with an insecticide will be
necessary under moderate to high population
densities. See section on IPM Practices for
Selected Pests (page 32).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
13
PETAL FALL
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Cultural Management
Reduce fruit corking.
Solubor
Borosol
+++
+++
1 lb
at first cover
1 pt
If boron is low in leaf sample or cork spot has
been a problem in past years, a second and
third application may be used. Dilute
applications are necessary for good uptake. See
Fertility Management section (page 44).
Reduce fruit corking and
bitter pit.
calcium nitrate
or
calcium chloride
+++
+++
3 lb
2 lb
beginning at
first cover
Repeat calcium sprays in each cover spray all
season. Calcium nitrate may contribute to
elevated leaf nitrogen levels and vegetative
growth. Do not apply calcium chloride when
temperatures are above 85°F, and DO NOT
tank mix with Solubor or Apogee. All calcium
sprays should be applied dilute for maximum
response, especially for bitter pit control in late
season cover sprays when fruit are becoming
waxy. See Fertility Management section (page
44).
Plant Growth Regulators
Reduce fruit russetting on
susceptible cultivars (esp.
Golden Delicious).
(GA4+7)
Pro-Vide 10SG
Novagib 10L
++++
++++
60 - 100 g
20-26 fl oz
12
4
None
At petal fall, begin the first of four applications
at 7- to 10-day intervals. See Growth-
Regulating Chemicals section (page 67) for
complete recommendations.
Thin fruit to reduce crop
load and encourage return
bloom.
Depends on cultivar, fruit
size, and thinning chemical
selected. Applications
timed from petal fall to
about 8 mm would be
applied during this time.
+++++
See thinning
chart on page
70.
Check label for specific
thinning chemical(s) to
be used.
See Chemical Fruit Thinning Spray and Apple
Thinning recommendations chart in Growth-
Regulating Chemicals section.
Initiate vegetative growth
control applications.
Apogee
++++
Use at TRV
calculated
A.I./acre.
12
45
See Apogee table in Growth-Regulating
Chemicals section (page 72).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
14
PETAL FALL (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Control scab.
Scout for secondary scab.
*****
If primary scab is controlled by petal fall or
first cover, switch to captan. If secondary scab
is detected early, dodine or an EBI fungicide
can be effectively used in a postsymptom
treatment. See discussion under Fungicides and
Bactericides (page 54).
Fungicides
captan 50W or
4L or
80W or
80WDG
2 lb
1 qt
1.25 lb
1.25 lb
8 lb
4 qt
5 lb
5 lb
96
96
24
24
0
0
0
0
If an EBI fungicide is used in this spray,
increase the rate of Captan 50W to 6 to 8
lb/acre or Captan 4L to 3 to 4 qt/acre and
extend interval to 10-14 days, or follow
combination sprays with lower rates of captan
or metiram in 5-7 days with full rate of captan
or combinations of captan plus mancozeb or
metiram. Captan and metiram at petal fall or
first cover generally give better fruit finish than
mancozeb. If the first cover spray occurs after
May 15, include 8 to 12 oz/acre of thiophanate-methyl
85WDG with captan for sooty blotch or
flyspeck control as directed in second and later
cover sprays below. Use captan in orchards
where black rot is a problem.
Control summer diseases
(general).
captan 50W or
4L or
80 W or
80 WDG
+
Polyram 80 W or
mancozeb
80W
75 DF
4F
+++++
+++++
+++++
+++++
+++++
1¼ lb
0.62 qt
0.79 lb
0.79 lb
¾ lb
¾ lb
¾ lb
0.6 qt
5 lb
2½ qt
3.15 lb
3.15 lb
3 lb
3 lb
3 lb
2.4 qt
96
96
24
24
96
96
96
96
0
0
0
0
77
77
77
77
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
15
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control summer diseases
(general) (continued).
Sovran 50WG
+++++
1.0 to 1.6 oz
4.0 to 6.4 oz
12
30
Sovran and Flint will also control apple scab
and powdery mildew.
Flint 50WG
+++++
—
2.5 to 3.0 oz
12
14
Pristine 38W
+++++
—
14.5 to 18.0 oz
12
0
Control Brooks fruit spot.
Fungicides
Use fungicides listed for
summer diseases or use
fungicide combinations
listed under green tip.
+++++
Petal fall through third cover sprays are the
most important sprays for Brooks spot control.
The EBI fungicides have very little Brooks
spot activity. If one of them is used, combine it
with a full rate of protectant.
Control powdery mildew
and cedar apple rust.
Fungicides
See tight cluster to pink
spray.
If captan alone is used in these sprays, a
fungicide with activity on powdery mildew or
cedar apple rust should be included in this
spray.
Insect Management
Preventively control
European red mite,
spotted tentiform
leafminer, and white
apple leafhopper.
Insecticides
Agri-Mek 0.15EC
+
oil
+++++
2.5 oz
10 oz
12
28
An application of Agri-Mek at petal fall should
provide season-long suppression of these pests.
A paraffinic spray oil (0.25% or 1 gal/acre)
must be tank mixed to ensure Agri-Mek’s
activity. Do not use captan 2 weeks before or
after applying oil with Agri-Mek.
Preventive control of
European red mite.
Apollo SC
Savey 50WP
Zeal 72WDG
Envidor 2SC
++++
++++
+++++
+++++
—
—
—
—
4 oz
3 oz
2 to 3 oz
16 to 18 oz
12
12
12
12
45
28
28
7
Apply one of these products between petal fall
and third cover or when mites reach one adult
per leaf. See page 38 for resistance
management of European red mite.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
16
PETAL FALL (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control plum curculio.
Insecticides
Avaunt 30WG
Actara 25SDG
Guthion 50WP
Imidan 70WP
Calypso 4F
Clutch 50WDG
Sevin 50WP
+++++
+++++
+++++
++++
++++
+++
+++
—
—
½ lb
¾ lb
—
—
½ lb
5 to 6 oz
4.5 to 5.5 oz
2 lb
3 lb
4 to 8 oz
3 oz
1 lb
12
12
48h, 14d
24
12
12
12
28
35
21
7
30
14
3
Adults begin to enter orchards near bloom,
with the majority of adults present by petal fall.
An insecticide applied at petal fall is essential
to minimize damage. Cool weather during this
period may extend adult activity, which may
require a second application 10 days later.
Read about re-entry intervals for Guthion in the
Insecticides and Miticides section (page 57).
Control Oriental fruit
moth.
Insecticides
Guthion 50WP
Imidan 70WP
Avaunt 30WG
Sevin 50WP
Assail 30SG
Calypso 4F
Clutch 50WDG
+++++
++++
++++
++++
++++
++++
+++
½ lb
¾ lb
—
½ lb
—
—
—
2 lb
3 lb
5 to 6 oz
2 lb
5 to 8 oz
4 to 8 oz
3 oz
48h, 14d
24
12
12
12
12
12
21
7
28
3
7
30
14
Oriental fruit moth has become more important
in apples in recent years. An insecticide
applied between 500 and 600 degree days (DD)
after biofix will control the first generation.
Read about re-entry intervals for Guthion in
Insecticides and Miticides Section (page 57).
First generation OFM is easily controlled with
all recommended insecticides.
Control San Jose scale.
Insecticides
Diazinon 50WP
Guthion 50WP
Esteem 0.86EC
Centaur 70WP
Movento 2SC
Assail 30SG
summer oil
+++++
++++
+++++
+++++
++++
+++
+++
1 lb
½ lb
—
—
—
—
—
4 lb
2 lb
4 oz
34.5 oz
6-9 oz
8 oz
1 to 2%
96
48h, 14d
12
12
24
12
12
21
21
45
14
7
7
0
Where scales have been a problem the previous
year, apply an insecticide for first generation
crawlers, which are active from petal fall
through third cover. Yellow crawlers can be
detected by wrapping double-stick tape around
infested limbs after bloom and inspecting
weekly. Caution: Diazinon or oil applied with
captan or Captec may cause phytotoxicity.
Control rosy apple aphid. Insecticides
Provado 1.6F
Actara 25WP
Assail 30SG
Calypso 4F
Movento 2SC
+++++
+++++
+++++
+++++
++++
2 oz
—
—
—
—
4 to 8 oz
4.5 oz
2.5 to 4.0 oz
2 to 4 oz
6 to 9 oz
12
12
12
12
24
7
35
7
30
7
If an insecticide was not applied for rosy apple
aphid at pink, or if control was poor, an
insecticide should be applied.
An adjuvant must be applied with Movento.
See section on Rosy Apple Aphid resistance
section (page 38).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
17
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control white apple
leafhopper.
Insecticides
Sevin 50WP
Actara 25WDG
Assail 30SG
Calypso 4F
Provado 1.6F
Avaunt 30WG
+++++
+++++
+++++
+++++
+++++
+++++
½ lb
—
—
—
1 oz
—
2 lb
2 to 2¾ oz
2.5 to 4.0 oz
2 to 4 oz
4 oz
5 to 6 oz
12
12
12
12
12
12
1
35
7
30
7
28
Threshold level for first generation white apple
leafhopper is 1 nymph per leaf. Thinning
apples with Sevin during this time controls
leafhoppers. Leafhoppers may be present from
petal fall to second cover spray.
Control spotted
tentiform leafminer.
Insecticides
Actara 25WDG
Delegate WG
Provado 1.6F
Assail 30SG
++++
+++++
++++
++++
—
—
1 to 2 oz
—
4.5 oz
4.5 oz
4 to 8 oz
1.1 oz
12
4
12
12
35
7
7
7
Threshold level for first generation leafminer is
one mine per leaf, but rarely do populations
reach this level this early in the season.
Control green
fruitworm.
Insecticides
See insecticides for codling
moth or tufted apple bud
moth control.
Green fruitworms are not a common pest:
Apply an insecticide at petal fall if larvae are
observed.
Weed Management
Control weeds.
Check orchards for weed
populations.
*****
Identify weed problems so herbicide program
can be adjusted for summer weed control.
Apply PRE +
Nonselective POST
herbicide.
See herbicide guide.
*****
See product labels.
See product labels.
Apply when summer weeds are 2 to 3 inches
tall. Delaying application of preemergence
herbicides until early May extends summer
weed control.
Suppress clover bloom
to protect bees from
insecticide sprays.
2,4-D *****
1 qt
48
60
Apply 2,4-D 7 to 10 days before spraying
insecticides to suppress clover and avoid
killing bees.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
18
FIRST COVER
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management (Same fungicides as used in Petal Fall Spray)
Insect Management
Control codling moth.
Monitor codling moth adult
activity.
Insecticides
Delegate 25WP
Altacor 35WDG
Voliam Flexi
Belt 4SC
Guthion 50WP
Imidan 50WP
Intrepid 2F
Rimon 0.83EC
Assail 30SG
Calypso 4F
CYD-X
*****
+++++
+++++
+++++
++++
++++
++++
++++
++++
++++
++++
++++
—
—
—
—
½ lb
¾ lb
—
—
—
—
—
4.5 to 7 oz
2.5 to 4.5 oz
4 to 7 oz
3 to 5 fl oz
2 lb
3 lb
10 to 16 oz
20 to 40 oz
4 to 8 oz
4 to 8 oz
1 to 3 oz
4
4
12
12
48h, 14d
24
4
12
12
12
4
7
14
35
14
21
7
14
14
7
30
0
See IPM Practices for codling moth (page
32) to determine how to minimize insecticide
applications for codling moth control.
Most insecticides generally provide 2 weeks’
control, so do not be concerned if pheromone
trap counts remain high 1 week after spraying.
If using Intrepid or Rimon (which are excellent
ovicides) for first generaton codling moth, 2
applications at 14-day intervals should be
made, the first at 100 DD.
CYD-X is a virus that controls only codling
moth. Frequent applications (7-10 days) at low
rates (1 to 2 oz per acre) have worked well in
field trials.
Codling moth insecticide-resistant populations
exist in some orchards and can affect the
performance of certain products.
Control rosy apple
aphid, plum curculio,
white apple leafhopper,
spotted tentiform
leafminer, and San Jose
scale.
Monitor orchards for these
insects.
Insecticides
(See Petal Fall section,
page 13)
*****
Infestations of these insects may occur anytime
from petal fall to the second cover spray. Early
detection is important for effective control.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
19
SECOND COVER AND LATER SPRAYS
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Cultural Management
Reduce fruit corking and
bitter pit.
calcium nitrate
calcium chloride
+++
+++
3 lb
2 lb
See information listed in Petal Fall to First
Cover sections (pages 13 through 18) and
Fertility Management section (page 44).
Apply second half of fertilizer to
mature, bearing trees if crop
load is present, as soon as
frost/freeze danger is past
(approx. second cover).
++++
See Fertility Management Recommendations
section (page 44) for fertilizer use suggestions
and complete recommendations.
Provide proper nutrition
for moderate tree growth
and good fruit quality.
Collect leaf samples in July to
mid-August for leaf analysis.
+++++
See Fertility Management Recommendations
section (page 44) for complete details.
Select lateral limbs, strip whorls,
establish wide crotch angles
with toothpicks or clothespins,
and prop limbs to good limb
angles (60-90° for central leader
trees and 75-85° below vertical
for high density, slender,
spindle-type trees).
++++
Tree training is mandatory to develop proper
lateral branching and limb position.
Achieve proper tree
training, and control tree
size and density for good
light and spray
penetration.
Do detailed young tree
management (deshoot, position
limbs, tie up leader growth)
every 6 to 8 weeks until full tree
size and bearing are achieved
(especially for high density
orchards).
++++ Summer pruning is a necessary extension of
tree training begun earlier. Summer pruning
helps contain tree size and density, and proper
limb selection and positioning encourage
flower initiation.
Remove water sprouts.
++++
Do leader manipulation, such as
summer bending or snaking,
every 18 inches of terminal
growth extension.
++
Removing upright water sprout growth reduces
tree density, allowing greater spray penetration
and better light distribution for fruit quality and
color development. Summer pruning and
removal of water sprouts also help control
sooty blotch and flyspeck.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
20
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness(+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Plant Growth Regulators
Thin to reduce crop load
and encourage return
bloom.
Depends on cultivar, fruit
size, and thinning chemical
selected. Application time
from approximately 9 mm
and larger would be applied
from second cover on.
+++++
See
thinning
chart on
page 70.
See Chemical Fruit Thinning Sprays (page 68)
and Apple Thinning Recommendations chart
(page 70) in Growth-Regulating Chemicals
section.
Enhance return bloom.
Fruitone L
Ethrel
+++
+++
2 oz
16-72
fl oz
48
96
Research studies in the Southeast have found
that NAA or Ethrel treatments can improve
return bloom. Ethrel rate depends on many
factors including cultivar and crop load. Refer
to table on page 69.
Control ground suckers
around base of trunk.
Tre-Hold A-112 Sprout
Inhibitor -
Also use herbicides approved
for sucker control. See notes
in Herbicide section (page
63) for Rely, Gramoxone.
++++
Use 10,000 ppm (10
oz/1 gal) as a low-pressure,
large-droplet
handgun application.
12
0
See Sucker Control (page 72) for specific
recommendation details.
Delay preharvest fruit
drop and delay fruit
maturity.
ReTain
+++++
2 oz
One 333-
gram
pouch per
acre (50 g
a.i.)
12
7
Single Pick Harvest. Applying one pouch of
ReTain per acre 4 weeks prior to the
anticipated beginning of the normal harvest
period of untreated fruit for the current season
will delay the harvest period by 7-10 days.
Multiple Pick Harvest. Applying one pouch
of ReTain per acre 1 to 2 weeks prior to the
anticipated beginning of the normal harvest
period of untreated fruit for the current season
will improve quality and storage potential of
later picked apples (2nd and 3rd pick fruit).
Applications at this time will not typically
delay the start of the harvest, but will help
control the maturation rate of the later harvests.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
21
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Delay or reduce
preharvest fruit drop or
both.
Preload NAA (Fruitone-L)
++++
2 oz
48
4
Apply multiple applications of 5 ppm each
week for the 4-week period prior to the
normal start of the harvest period for each
variety.
NAA (Fruitone L)
+
4 to 8 oz
48
4
Temporarily suppress any fruit drop by
applying 10 to 20 ppm (depending on
variety) of NAA. A second application can
be applied 7 to 10 days later. See Growth-
Regulating Chemicals section (page 67) for
details.
Reduce fruit russetting
in susceptible varieties.
Pro-Vide 10SG
Novagib 10L
(continue applications started
at petal fall)
++++
++++
60-100 g
20 oz per
acre/appl
12
4
0
See Growth-Regulating Chemicals section
(page 67) for recommendation details.
Pro-Vide 10SG
+++
100-200 g
12
0
Reduce fruit cracking of
susceptible varieties
(e.g., Stayman).
Novagib 10L
+++
2 to 4 pt per
acre/appl
4
Begin applications in early to mid June or
as soon as cracking is observed. Repeat at
3-week intervals until harvest. See Growth-
Regulating Chemicals section (page 67) for
details.
Promote lateral
branching of current
season=s growth.
Promalin
+++
0.8 oz/gal of
water (125 ppm)
12
None
See Growth-Regulating Chemicals section
(page 67) for recommendation details.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
22
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Disease Management
Scout orchard.
Prune out fire blight strikes.
*****
*****
Fungicides
captan
50W or
4L or
80W or
80WDG
+++++
+++++
2 lb
1 qt
1.25 lb
1.25 lb
8 lb
4 qt
5 lb
5 lb
96
96
24
24
0
0
0
0
Control summer diseases
(white rot, bitter rot,
black rot, sooty blotch,
flyspeck, black pox).
ziram 76DF or 76WDG
++++
2 lb
8 lb
48
14
Apply cover sprays at 10- to 14-day
intervals. Use a 7- to 10-day interval during
wet, rainy periods. If thiophanate-methyl is
not used in cover sprays, it is important to
combine captan with sufficient ziram to
increase fungicide rate to 8 to 10 lb/acre in
order to control sooty blotch and flyspeck.
Be sure to observe 77-day preharvest
interval when using metiram or mancozeb.
When using a combination of captan and
ziram, use approximately equal rates of
each. Use captan where there is a history of
white rot.
Sovran 50WG
+++++
1.0 to 1.6 oz
4.0 to 6.4 oz
12
30
A maximum of four applications and 25.6
oz of Sovran 50WG can be used per acre
per season. It is weak on black pox.
Flint 50WG
+++++
—
2.5 to 3.0 oz
12
14
A maximum of four applications and 11 oz
of Flint 50WG can be used per acre per
season. It is weak on black pox.
Pristine 38W
+++++
—
14.5 to 18.0
oz
12
0
captan
50W or
4L or
80W or
80 WDG
+
thiophanate-methyl 85WDG
+++++
2 lb
1 qt
1.25 lb
1.25 lb
2 to 4 oz
8 lb
4 qt
5 lb
5 lb
8 to 16 oz
96
96
24
24
96
0
0
0
0
1
A maximum of four applications and 72 oz
of Pristine can be used per acre per season.
Pristine has activity on strains of the
Alternaria blotch fungus that are resistant to
Sovran and Flint. It is weak on black pox.
If Captan 80W or 80WDG is used then the
REI is 48 hours for this and other
combinations below.
ziram 76DF or 76WDG
+
thiophanate-methyl 85WDG
+++++
2 lb
2 to 3 oz
8 lb
8 to 12 oz
48
14
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
23
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*) 100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control summer diseases
(continued).
captan
50W or
4L or
80W or
80 WDG
+
metiram 80DF
or
mancozeb 75DF
+++++
1.25 lb
1 pt
0.79 lb
0.79 lb
¾ lb
¾ lb
5 lb
2.5 qt
3.15 lb
3.15 lb
3 lb
3 lb
77
77
Metiram and mancozeb cannot be used
within 77 days of harvest.
captan
50 W or
4 L or
50W or
50WDG
+
ziram 76DF, 76WDG
+
thiophanate-methyl 85WDG
+++++
1 lb
½ qt
0.63 lb
0.63 lb
1 lb
2 to 4 oz
4 lb
1 qt
2.52 lb
2.52 lb
4 lb
8 to 16 oz
96
14
captan
50 W or
4 L or
80W or
80WDG
+
ProPhyt3
+++++
2 lb
1 qt
1 ¼ lb
1 ¼ lb
½ to ¾ qt
8 lb
4 lb
5 lb
5 lb
2 to 3 qt
96
0
This combination is effective on Glomerella
leaf spot. Make the first spray around June
15th or when first leaf spot symptoms
appear and continue spraying every 7-10
days until harvest. Use a 7-day interval
when it is warm and wet. Use high rate of
ProPhyt where Glomerella leaf spot is a
problem. Rotations with Pristine or Flint are
also effective.
The REI is 24 hours if Captan 80W or
80WDG is used.
Suppress necrotic leaf
blotch on Golden
Delicious.
ziram 76W or WDG
zinc oxide 39.8%
+++++
+++++
1 to 2 lb
4 to 8 lb
1 pt
48
0
14
0
Sprays from mid June through early August
are most important.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
3Other phosphite fungicides are also labeled on apples. See the discussion of phosphite fungicides in the Fungicides and Bactericides section (p. 54).
24
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
interval
(days) Comments
Control powdery
mildew.
Scout orchard.
*****
Determine need for additional fungicides
based on the number of infections on newly
unfolded leaves.
Control Alternaria
blotch.
Pristine 38W
+++++
14.5 to 18.5 oz
12
0
Make first application of Pristine around
third or fourth cover (mid June). Apply two
additional applications at 10- to 14-day
intervals. These applications will also control
other summer diseases on Delicious.
Rotations of Pristine and captan plus a
phosphite fungicide are also effective and
will help limit QoI fungicide use since only 4
sprays are allowed by the label. Use in
conjunction with a preventive mite
management program. Do not make more
than 4 applications or apply more than 72 oz
of Pristine per season.
Insect Management
Monitor pheromone traps
weekly for adult activity.
*****
Insecticides
(See First Cover.) *****
Control codling moth
and Oriental fruit moth.
OFM Mating Disruption
Isomate-M100
CheckMate OFM-F
+++++
+++++
100
1 to 2 oz
See IPM practices for codling moth (page
32) and Oriental fruit moth (page 33) to
determine the need for and timing of
insecticide sprays. Keep trap bottoms clean,
and replace lures at recommended intervals.
If a combination codling moth/Oriental fruit
moth mating disruption product is not used,
OFM populations often increase later in the
season (August and September). Isomate-
M100 applied in June or sprays of
CheckMate OFM-F in July and/or August
will usually control late-season populations.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
25
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control tufted apple
bud moth.
Monitor pheromone traps
weekly for adult activity.
Thin fruit to avoid
excessive clustering.
*****
****
See IPM Practices for tufted apple bud moth
(page 34) to determine the proper timing of
insecticide applications.
Clustering of fruit is conducive to higher
levels of tufted apple bud moth injury.
Insecticides
Intrepid
Delegate 25WG
Altacor 35WDG
Voliam Flexi
Belt 4SCV
+++++
+++++
+++++
+++++
+++++
—
—
—
—
—
6 to 12 oz
4.5 to 7 oz
2.5 to 4.5 oz
4 to 7 oz
3 to 5 fl oz
4
4
4
12
12
14
7
14
35
14
See Insecticide Resistance Management
section (page 37) for tufted apple bud moth
(TABM). Insecticide sprays for TABM are
recommended only in orchards with a history
of damage. See section on IPM practices for
TABM (page 34) to properly time sprays.
Bacillus thuringiensis
Dipel 2X
CryMax
XenTari
+++
1 to 2 lb
1 to 2 lb
1 to 2 lb
4
4
4
0
0
0
For best results apply Bacillus thuringiensis
(Bt) products at no less than 2X
concentration. If using Bts, it is important
to monitor codling moth with pheromone
traps because Bts do not control CM.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
26
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control apple maggot.
Erect red sticky spheres in
early June to monitor
adults.
****
Erect sticky traps baited with fruit essence
lures on outside rows nearest abandoned
orchards or other sources of flies. Check
weekly. Threshold level is a cumulative of 5
flies per trap. If the threshold is exceeded
again 2 weeks after spraying, apply again.
Adults can emerge from June through
September. Historically, peak emergence
generally occurs from mid July to early
August.
Insecticides
Guthion 50WP
Imidan 70WP
Assail 30SG
Calypso 4F
Provado
Surround WP
+++++
++++
+++
+++++
++++
+++
½ lb
¾ lb
—
—
—
—
2 lb
3 lb
8 oz
4 to 8 oz
6 to 8 oz
20 to 50 lb
48h, 14d
24
12
12
12
4
21
7
7
30
7
C
Apply Surround at 7- to 14-day intervals, or
after a heavy rain, because thorough,
uniform, and consistent coverage is
important. Rate of Surround will vary with
tree size.
Control white apple
leafhopper or potato
leafhopper.
Insecticides
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Avaunt 30WG
Clutch 50WDG
Centaur 70WP
+++++
+++++
+++++
+++++
+++++
+++++
+++++
1 oz
—
—
—
—
—
—
4 oz
2 to 2¾ oz
2.5 to 4.0 oz
2 to 4 oz
5 to 6 oz
2 oz
34.5 oz
12
12
12
12
12
12
12
7
14
7
30
28
14
14
Threshold level for second brood white apple
leafhopper nymphs (which occur in late July
to early August) is one nymph per leaf.
Treatment will eliminate the need to treat for
adults immediately before harvest.
Generally, low rates of insecticides will
control leafhoppers.
Control brown
marmorated stink bug.
Insecticides
Actara
Bifenthrin 2EC
Danitol 2.4EC
Warrior 1CS
+++
+++
+++
+++
4.5 to 5.5 oz
2 to 2.4 fl oz
16 to 21.6 fl oz
2.56 to 5.2 fl oz
12
12
24
24
35
7
14
21
Brown marmorated stink bug is a new pest,
and there is an incomplete knowledge base
on the efficacy of various insecticides.
Insecticides recommended in 2011 are based
on their efficacy against native stink bugs.
Check with your extension office for updated
information as the 2011 season progresses.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
27
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
interval
(hours)
Preharv.
interval
(days) Comments
Control spotted
tentiform leafminer.
Insecticides
Lannate 90SP
Delegate WG
Vydate 2L
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Clutch 50WDG
++++
+++++
++++
+++
++++
++++
++++
++++
¼ lb
—
1 to 2 pt
2 oz
—
—
—
—
1 lb
4.5 to 7 oz
4 to 8 pt
8 oz
4.5 oz
2.5 oz
2 to 4 oz
3 oz
72
4
48
12
12
12
12
12
14
7
14
7
14
7
28
14
A threshold level of two mines per leaf for
second generation larvae (June to July)
should be used to dictate the need for
STLM control. Control of third generation
larvae (August) may be necessary on late-maturing
cultivars if populations exceed 4
mines per leaf. Many orchards have high
levels of parasites by this time, which
usually precludes the need for insecticides.
Insecticides are more effective against sap-feeding
mines than tissue feeders.
Control green apple
and spirea aphids.
Insecticides
Provado 1.6F
Actara 25WDG
Assail 30SG
Calypso 4F
Clutch 50WD
+++++
+++++
+++++
+++++
+++++
1 to 2 oz
—
—
—
—
4 to 8 oz
4.5 oz
2.5 to 4.0 oz
2 to 4 oz
2 oz
12
12
12
12
12
7
35
7
28
14
Threshold level for green apple aphid is
50% infested terminals. Control is most
important on young trees and in dwarf
plantings. On mature trees, a higher
threshold is tolerable.
Control Comstock
mealybug.
Insecticides
Diazinon 50WP
Actara 25WDG
Assail 30SG
Movento 2SC
+++++
+++
+++++
+++
1 lb
—
—
—
4 lb
4.5 oz
4 to 8 oz
6 to 9 fl oz
96
12
12
24
21
35
7
7
Applications should be made near the
second or third cover spray. Comstock
mealybug is an unpredictable pest, and
orchards with a history of problems are
most susceptible.
Control woolly apple
aphid
Insecticides
Provado 1.6F
Movento 2SC
Diazinon 50WP
++
++
+++++
—
—
1 lb
6 to 8 fl oz
6 to 9 fl oz
4 lbs
12
12
24
7
7
21
Woolly apple aphid control can be difficult
if insecticides are applied after populations
reach large densities. Use a threshold of
10% infested shoots.
An adjuvant must be used with Movento.
Control redbanded
leafroller.
Insecticides
See insecticides for tufted
apple bud moth.
Redbanded leafroller is a sporadic problem.
If damage is done, it is usually by the last
generation, which lays eggs from mid
August to mid September.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
28
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Control lesser apple
worm.
Insecticides
See insecticides for codling
moth.
Lesser apple worm is a sporadic pest of
importance in isolated areas. If damage
occurs, it is usually by the third generation,
which occurs in August.
Control dogwood
borer.
Insecticides
Lorsban 50W,
4E
++++
+++++
3 lb
1.5 qt
—
—
96
96
28
28
Apply insecticides with a handgun sprayer
to the trunk, especially to burr knots and
graft unions. Moths can lay eggs from mid
May through September, so treatment
before July is optimal. Lorsban should be
applied with a handgun sprayer from no
more than 4 ft or with a shielded sprayer to
prevent drift onto foliage or fruit.
Control European red
mite and two-spotted
spider mite.
Monitor trees for mite
activity.
*****
See IPM practices for European red
mite. European red mite and two-spotted
spider mite threshold levels before July are
7 mites per leaf (85% infested leaves) and
10 mites per leaf (90% infested leaves)
during July and August. If populations are
near threshold level and Stethorus punctum
is present, recheck in 3 to 4 days to
determine if biological control reduces
mite populations. In orchards with
Alternaria blotch, a threshold of 1 mite/leaf
(50% infested leaves) should be used to
minimize stress to trees.
Miticides
Acramite 50WS
Nexter 75WP
Portal 0.4EC
Apollo SC
Savey 50DF
Zeal 72WDG
Envidor 2SC
Vendex 50W
wettable sulfur
summer oil
+++++
++++
+++++
++++
++++
+++++
+++++
++++
+
++
—
—
—
—
—
—
—
¼ lb
1½ to 3½ lb
½ to 1 gal
¾ to 1 lb
4.4 oz
1 to 2 pt
4.0 oz
3.0 oz
2 to 3 oz
16 to 18 oz
2 lb
5 to 15 lb
½ to 1% soln.
12
12
12
12
12
12
12
48
12
12
7
25
14
45
28
28
14
14
7
0
If Apollo or Savey were used at petal fall,
do not reapply at this time. Do not expect
complete control with a single application
of oil or sulfur. These materials must be
applied multiple times for best results.
Applying a highly refined summer oil
when mite populations are beginning to
increase (first and second covers) will help
suppress European red mite infestations.
Do not apply captan 2 weeks before or
after an oil spray.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
29
SECOND COVER AND LATER SPRAYS (continued)
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Weed Management
Spot-treat with
herbicide to control
difficult-to-manage
perennial weeds.
glyphosate *****
++++
See Weed Response to
Herbicide table
(pages 51 to 53).
4 1 Apple trees are especially sensitive to
glyphosate applied in late summer and fall.
Avoid contacting tree bark and especially
foliage.
Bermudagrass control. Poast *****
++++
1.5 pt
followed by
1 pt
12 14 Apply when bermudagrass has 4 to 6-
inches of new growth in spring. Follow
with a second application when
bermudagrass has 4 inches of regrowth.
POSTHARVEST
Rate per2
Goals Options
Relative1
Effectiveness (+)
or
Importance (*)
100 gal Acre
Re-entry
Interval
(hours)
Preharv.
Interval
(days) Comments
Plant Growth Regulators
Control fruit storage
scald.
DPA
++++
2½ pt per one gal of
water as a dip or spray
to harvested fruit.
See Growth-Regulating Chemicals section
(page 67) for complete details.
To maintain apple flesh
firmness, fruit acidity and
minimize scald.
SmartFresh
++++
See Growth-Regulating Chemicals section
(page 67) for complete details.
Weed Management
Apply POST or PRE +
POST herbicide.
See herbicide guide.
***
See herbicide guide.
See product labels.
In areas where heavy populations of winter
annual weeds are present, apply herbicide as
part of vole management program. Application
of a fall preemergence herbicide will delay the
spring herbicide application to early May or
later.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
30
Tree Row Volume (TRV):
A Model for Determining Spray Volume
The TRV model is a simple and objective method of determining (1) the volume of tree
canopy on an acre of orchard, regardless of row spacing, tree size, age, or other factors; and
(2) the dilute application water rate and chemical quantity for dilute (1X) applications or
concentrate chemical load per acre needed to effectively spray each particular orchard,
regardless of pruning and tree canopy density.
The TRV concept rests on these assumptions: Each row of trees is a wall of foliage, and
water and chemical loads required can be related to the volume and density of foliage
within that wall. Only three measurements must be made: (1) The distance between rows of
trees; (2) the maximum tree height to be sprayed; and (3) the spread from drip line to drip
line, which must be accurately measured to at least the nearest foot. In addition, an
assessment of tree density is needed to calculate the TRV of an orchard.
Using these measurements, the TRV of any orchard can be calculated using the following
formula:
Step 1:
Step 2: Feet of row/acre (from Step 1) X tree height (ft) X cross-limb spread (ft) = cu ft of
foliage/acre.
Steps 1 and 2 determine the volume of foliage canopy per acre in the orchard.
Step 3: Select one of the numbers from Table 1 that best indicates the canopy density of
each separate orchard or block.
The cubic feet of foliage volume from Step 2 and the tree density established in Step 3 are
used to calculate the water volume required per acre for a dilute spray application to
provide maximum chemical load with a dilute airblast sprayer (applied to runoff).
Step 4:
cu ft of
foliage/acre canopy density
(from Step 2) X (from Step 3) =
1,000 cu ft
gallons of dilute solution
to be applied per acre for
a maximum application
Example
Consider an orchard that has rows spaced 25 feet apart, trees 20 feet high, a spread of 17 feet
from drip line to drip line, and a tree density of 0.85.
Step 1:
Step 2: 1,742.4 ft X 20 ft X 17 ft = 592,416 cu ft
Step 3: Density has been given as 0.85 gal/1,000 cu ft
Step 4:
However, general pesticide applications are not applied to runoff. Using 70 percent (0.70) of
the “to runoff” calculated rate reduces the dilute application just to the point of drip, or what
we call “pesticide dilute.” Table 2 gives the adjustments to the “TRV calculated water rates
for dilute to runoff” water application rate for various chemicals used and types of spray
applications. The 503.5 gallons per acre in the example above is used to illustrate the
adjustments in Table 2.
Table 1. Canopy density adjustments in tree row volume (TRV) model.
0.70 gal/1,000 cu ft
Trees extremely open, light visible through entire tree, less
than 15 scaffold limbs per tree or young tree.
0.75 gal/1,000 cu ft
Trees very open, 18 to 21 scaffolds per tree, light penetration
throughout tree, healthy spurs within tree canopy.
0.80 gal/1,000 cu ft
Trees well pruned, adequate light in trees for healthy spurs
throughout trunk and scaffold limbs, many holes or openings
in foliage where light is visible through tree.
0.85 gal/1,000 cu ft
Trees moderately well pruned, reasonable spur population
within canopy, tree thick enough that light is not visible
through bottom ⅔ of tree.
0.90 gal/1,000 cu ft
Trees pruned minimally, spurs inside canopy are weak due to
limited light, very few openings where light is visible
throughout the tree.
0.95 gal/1,000 cu ft
Little or no pruning, spurs dead or very weak in canopy, very
little light visible throughout the tree.
1.00 gal/1,000 cu ft
Tree unpruned, extremely thick, no light visible anywhere
through tree canopy, trees more than 20 ft high.
43,560 sq ft/acre
distance between rows (ft) = feet of row/acre
43,560 ft2
25 ft = 1,742.4 ft
592,416 cu ft X 0.85 gal
1,000 cu ft = 503.5 gal/acre will apply a dilute
application to runoff.
31
Table 2. Adjustments in tree row volume (TRV) calculated water rates per acre for
various chemicals and types of spray applications.
Type of spray and chemical
application
% of the calculated TRV
dilute to runoff gallonage to
be used for a dilute
application
Actual gallons/acre
to be used in
previous TRV
example orchard
1Pre-petal fall dilute pesticide
application (adjusted because
of incomplete foliage
development)
56
282
Dilute pesticide application
(from petal fall on and all
other applications not
specifically mentioned)
70
352
ProVide and Promalin
(as a fine mist)
40 to 50
201 to 252
Spur Red Delicious thinners
and dormant oil applications
100
504
Thinners for other varieties
70 to 90
352 to 453
Vegetative growth inhibitor
80 to 90
403 to 453
Preharvest Ethrel plus stop-drop
spray
100 to 120
504 to 605
1To use this reduced gallonage requires accurate nozzling to top of trees and good air displacement within
trees (i.e., reduced tractor speed).
Table 3 demonstrates how the chemical load and water volume for concentrate sprays can
be easily calculated from the TRV model.
The TRV model is accurate for dilute and concentrate chemical applications with
conventional airblast sprayers, using water volumes as low as 150 gallons per acre. Below
this gallonage, the physics of droplet size and impingement on the foliage can become a
limiting factor in obtaining effective deposition on trees. Thus, if the TRV model calculates
a water application rate of less than 150 gallons per acre, a 150 to 200 gallon rate should be
considered a minimum in a conventional airblast sprayer, or be sure you are using a
concentrate engineered sprayer (higher air speed) that will ensure adequate impingement of
the spray solution on the tree surfaces at low water volume.
Table 3. How to calculate concentrate application rates.
Concentrate
pesticide
application
(3X water
rate)1
Dilute pesticide TRV gallonage 352 gal/acre
Concentrate rate = 3X = 117 gal/acre
Concentrate
pesticide
chemical load
per acre
(2X to 4X)2
Rate of pesticide
per 100 gal X
Dilute pesticide
TRV gal/acre 2.0 X 352
100 gal
=
100
= 7.1 lbs/acre
5X or greater3
Rate of
pesticide per
100 gal X
Dilute
pesticide TRV
gal/acre X 0.8 = 2.0 X 352 X 0.8 =
100 gal 100
5.6
lbs/acre
1Assume the example orchard was to be sprayed at 3X concentration.
2Rate per 100 gal dilute. Example based on 2.0 lb pesticide/100 gal.
3This adjustment for concentrate application (5X or greater) should be made if spraying conditions are good
and trees are properly matched to the sprayer. Adequate spray coverage cannot be assumed with concentrate
application if sprays are applied during windy conditions or to thick, oversized trees.
Dwarf High-Density Orchards
Dwarf high-density orchards represent a special situation for TRV applications. Most high
density orchard TRV water application rates calculate out at well below the minimum
desirable gallonage for good droplet impingement (below 150 gallons/acre). We have
consistently found improved efficacy of pesticide application and improved time efficiency
by calibrating for double the TRV. This raises the water application rate above the minimum
desirable gallonage, and then you must drive every other row middle to reduce actual water
volume per acre of orchard back to true TRV calculated rate. Pesticides are applied on a
normal interval, alternating drive middles.
The reality of sprayer calibration and nozzling for chemical applications is that until the
proper chemical load is appropriately delivered and deposited on leaf and fruit surfaces, the
spray you apply cannot be considered an effective pesticide application.
32
IPM Practices for Selected Pests
Plum Curculio
Adults overwinter in leaf litter in and around orchards. In the spring when the daily
maximum temperature exceeds 70°F, adults emerge, mate, and lay eggs under fruit skin.
Adults generally begin to enter orchards shortly before bloom, but depending on weather
conditions, new adults can continue to enter until shortly after petal fall. An insecticide
application at petal fall is important to minimize damage when adults are present. Adults
are ¼-inch-long weevils with a curved snout; they are mottled black, gray, and brown with
two bumps on each wing cover and a white marking across the back. Eggs hatch within a
few days after being laid and feed in the fruit. The mature larva is ¼-inch long, white,
slightly curved, and legless. Damage on apples is usually observed as feeding or oviposition
scars and is cosmetic. There are two generations per year in most areas of the Southeast.
Scouting and Control: After bloom, check twice weekly for plum curculio adults or feeding
and egg-laying scars. Typically, an insecticide at petal fall is sufficient for control, but
occasionally emergence may be protracted and a second application at first cover may
further suppress damage.
Apple Maggot
The apple maggot usually completes one generation per season at elevations above 2,000
feet and two generations at less than 1,200 feet. However, depending upon the year, fly
activity can extend from June through September. Adult fly emergence from overwintering
pupae in the soil is unpredictable and can occur from late May to August, but the peak
emergence is usually between mid July and early August. About 7 days after emergence,
flies become sexually mature and mate, after which females deposit eggs under the skin of
apples by puncturing them with their ovipositor. After a few days a small maggot hatches
from the egg, and the maggot tunnels within the fruit. When mature, the maggot exits the
apple, drops to the ground, and burrows into the soil, where it completes development and
forms a pupa. The pupa is the overwintering stage, and it emerges as a fly the following
summer. If fly emergence is early in the season, some of their progeny emerge the same
season rather than overwinter. In addition, a small percentage of flies may not emerge until
2 to 4 years later.
Weather conditions are important in dictating the timing and length of fly emergence. Pupae
that are overwintering in lighter soils and in sunny areas emerge before those in heavier
soils and shady areas. Sufficient soil moisture is also necessary for flies to emerge from
soil-borne pupae. Drought delays or prevents many flies from emerging. Also, abandoned
orchards (or even a few nonsprayed trees) and wild hawthorn trees adjacent to apples are
potential sources of flies, and are a threat to commercial orchards located within a distance
of about 400 yards.
Monitoring and Control: Monitor apple maggot adults with red sticky spheres that are
baited with a fruit essence lure. Baited spheres catch two to four times as many adults as
nonbaited spheres. In orchards with no history of maggot injury, a minimum of three red
spheres should be placed on the outside row of an orchard closest to the suspected source of
flies (e.g., abandoned orchard). Hang spheres in trees with fruit, and remove the fruit
adjacent to the sphere. In orchards with a history of damage, also place traps within orchards
on the southern side of trees. When using baited spheres, apply an insecticide after catching
five flies cumulatively. Repeat an application at 14-day intervals if captures again reach 5
flies. Because the timing of emergence is difficult to predict, insecticide sprays should not be
based on population trends of the previous year.
Codling Moth
Codling moths begin to emerge and mate during April or early May, depending on location,
and complete two generations per season. Depending on location and the year, a partial or
complete third generation may occur. Eggs generally begin to hatch near the first cover
spray, and soon larvae tunnel into and feed inside fruit. The mature larvae are similar to
Oriental fruit moth larvae, being ½-inch long and pinkish-white with legs. Unlike the OFM,
codling moth larvae do not have an anal comb.
In recent years the codling moth has become a serious problem in orchards throughout the
Southeast. Factors associated with problem orchards are (1) bin piles stored near orchards
and/or (2) insecticide-resistant populations. Bins are an ideal environment for overwintering
larvae, and when they complete their development the following spring the adults disperse to
nearby orchards. Recent research suggests that orchards within 100 to 150 yards of bin piles
are particularly prone to infestation. Insecticide resistance has been detected in a number of
orchards where problems have persisted for one or two years.
Codling Moth Degree-Day Model
The codling moth degree-day model is used to predict adult emergence and egg hatch of
each of the two to three generations that occur each year. The model has been in existence
for more than 30 years, and it has worked well throughout the US. However, the model may
not be entirely accurate where insecticide-resistant populations occur or where bin piles are a
source of codling moths, because these moths emerge later than predicted by the model.
Base a decision to spray insecticides against codling moth on pheromone trapping and the
codling moth degree-day model. Use pheromone traps to determine the starting point of the
model (biofix) and to gauge the intensity of populations. The degree-day model predicts
percent of adult emergence and egg hatch for each of the two to three generations of codling
moth that annually occur in the Southeast. The model is quite accurate for the first
generation, but is less accurate for subsequent generations.
To use the model, begin to accumulate degree days when male flight begins in the spring,
which is referred to as biofix. The biofix date is determined with pheromone traps to detect
the first sustained catch of two or more moths in the spring. Traps should be placed in
orchards near the tight cluster stage of bud development, and checked one to two times per
week. Hang traps at a density of one trap per 10 acres of orchard. Traps hung in the upper
third of the canopy catch more moths than those in the lower canopy and are a preferred
location. Once biofix is determined, degree days are calculated daily. It is only necessary to
check traps once per week after biofix is determined. Use the table on page 36 to determine
the number of degree days occurring at various maximum and minimum daily temperatures.
33
First Generation: Recommendations are provided for low- and moderate-to-high population
densities. Low-density orchards are those with less than 0.5 percent of the fruit damaged the
previous year and pheromone trap catches that do not exceed 10 moths per trap per week
anytime during the first generation (to about 850 DD after biofix).
In low-density orchards, make a single insecticide application at 350 DD after biofix. In
moderate-to high-density orchards, apply two insecticide applications 14 days apart, the first
at 150 to 250 DD after biofix: 100 to 150 if using a product which depends primarily on
ovicidal activity for control (i.e., Intrepid or Rimon), and 250 if using an insecticide that
targets early stage larvae. Additional applications may be necessary if trap captures remain
high (greater than 7 moths per trap).
A second emergence of overwintering adults sometimes occurs between 500 and 800 degree
days after biofix. This is often referred to as the “B peak” and may be associated with
insecticide-resistant individuals in the population. Hence, pheromone trapping is important
throughout the flight period.
Second Generation: Recommendations are provided for extremely low, low, and moderate-to-high
population densities. Extremely low-density orchards may not require an insecticide
application (no first-generation damage is observed and pheromone trap catches remain below
one moth per trap per week between 1,000 and 2,000 DD after biofix). Low-density orchards
require one insecticide application, and recent research indicates the optimum timing is 1,400
to 1,500 DD. These orchards may have no sign of damage by first generation larvae and trap
catches between 3 to 7 moths per trap per week between 1,000 to 1,500 DD after biofix.
Moderate-to high-density orchards will have fruit damage and higher pheromone trap catches
requiring at least two insecticide applications at 14-day intervals, starting about 1,400 DD
after biofix.
Third Generation: The model should not be relied upon alone for timing insecticide
applications for the third generation, because the model becomes less accurate over time.
Exceptions to the Model: Where codling moth populations are extremely high and where
pheromone trap catches remain high between generations, additional insecticide applications
at shorter intervals may be necessary. This often occurs in orchards adjacent to an abandoned
orchard or where bins are placed near an orchard.
Relationship between degree-day accumulations from biofix and percentages of
co dling moth adult emergence and egg hatch.
Cumulative
Degree Days
% Adult
Emergence
% Egg
Hatch
Cumulative
Degree Days
% Adult
Emergence
% Egg
Hatch
0 (biofix)
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1,000
1,050
1,100
1,150
1,200
1,250
1
5
15
27
40
52
63
72
80
87
91
95
97
98
99
99
100
0
1
2
5
8
13
18
26
35
0
0
0
0
0
3
9
18
30
42
54
64
73
81
87
92
95
97
98
99
100
0
1
2
3
6
1,300
1,350
1,400
1,450
1,500
1,550
1,600
1,650
1,700
1,750
1,800
1,850
1,900
1,950
2,000
2,050
2,100
2,150
2,200
2,250
2,300
2,350
2,400
2,450
2,500
2,550
43
52
60
68
77
80
85
89
92
95
97
99
0
2
4
7
10
15
20
25
31
38
45
52
59
65
10
15
21
28
36
45
63
62
69
75
81
85
89
92
95
94
99
100
3
5
8
12
16
21
27
31
Oriental Fruit Moth
Oriental fruit moths begin to emerge and mate before apple bloom, and eggs begin to hatch at
petal fall. Variable spring temperatures cause erratic emergence and egg laying by first-generation
moths. The larvae feed on shoot tips and inside apple fruit. The mature larva is ½-
inch long, pinkish-white, and has an anal comb and legs. The only way to distinguish between
Oriental fruit moth and codling moth larvae is to use a hand lens to examine mature larvae for
the presence of an anal comb. Codling moth larvae do not have an anal comb.
Oriental Fruit Moth Degree-Day Model
Base a decision to spray insecticides against Oriental fruit moth on pheromone trap catches and
a DD model. The biofix is determined in the same manner as for the codling moth. Use
pheromone traps to determine the starting point of the model and to gauge the intensity of
populations. The degree-day model predicts adult emergence and egg hatch for the first three
34
generations of the four or five generations that occur in the Southeast. However, generations
overlap in the late season, which makes the degree-day model less useful later in the season.
The table on page 36 uses daily maximum and minimum temperatures to determine daily DDs
for Oriental fruit moth (base 45°F). Place traps in the orchards near the green-tip stage of bud
development, and check one to two times per week. Hang traps at eye level at a density of 1
trap per 10 acres of orchard. Check traps weekly after the biofix date.
First-Generation OFM: Control of the first generation is often important to prevent first-generation
damage and to reduce populations of subsequent generations. First-generation egg
laying is usually low on apple, and only one insecticide application between 400 and 500 DD
after biofix is necessary, which usually coincides with petal fall.
Second-Generation OFM: If first-generation control was successful, second-generation
populations are usually very low. Extremely low-density orchards may not require an
insecticide application (pheromone trap catches never exceed 3 moths per trap per week
between 800 to 1,600 DD after biofix). In low-density orchards (3 to 5 moths per trap per
week caught between 800 and 1,500 DD), make a single insecticide application at 1,400 DD.
Moderate- to high-density orchards will have fruit damage, higher pheromone trap catches, or
both, and may need two insecticide applications 14 days apart starting at 1,100 DD.
Third-Generation OFM: An insecticide is recommended at 2,200 DD after biofix if
pheromone trap catches exceed 5 moths per trap per week at 1,900 DD after biofix and if there
is fruit damage caused by the second generation.
Fourth-Generation OFM: Because of overlapping generations late in the season, it is difficult
to predict when egg hatch of the fourth generation begins. However, continuous egg laying
can occur from August through October, and pheromone traps are the best method to
determine the potential for late-season damage. Apply an insecticide within 7 to 10 days of a
pheromone trap threshold of 7 moths per trap per week.
Tufted Apple Bud Moth
The tufted apple bud moth (TABM) is the most common leafroller occurring on apple in the
Southeast. TABM completes two generations per year, with egg laying occurring during June
(first generation) and August and September (second generation). Larvae feed on leaves and
fruit, with fruit damage usually observed as surface feeding. However, second-generation
larvae often feed within the calyx end of fruit. Unless an individual orchard has a history of
damage by this insect, it is doubtful that special precautions need to be taken. Timing is
critical to the successful management of this pest. Depending on the type of insecticide used
and the intensity of the TABM population, one or two applications during each of the two
generations may be necessary. Maintain a clean orchard floor, particularly in the early spring
before bloom, to minimize TABM populations by removing the food source for overwintering
larvae. New apple sucker growth and broadleaf weeds are important food sources in the
spring. In recent years TABM populations have been reduced to very low numbers because of
new, more effective insecticides used in many orchards.
Tufted Apple Bud Moth Degree-Day Model
A TABM degree-day model similar to that of the Oriental fruit moth and codling moth has
been tested and modified for populations in the Southeast. For calculating degree days from
maximum and minimum daily temperatures, use the Oriental fruit moth table on page 35
(45°F). Place TABM pheromone traps at the tight cluster to pink stage of bud development at a
density of 1 trap per 20 acres of orchard. Biofix is the first date on which a sustained catch
occurs and may vary from 2 to 15 moths per trap over a one-week period. The cumulative
number of degree days from the point of biofix is used to predict percentage of egg hatch and
to time insecticide applications against the first generation.
First-Generation Recommendation: When population densities are sufficiently high or if a
short residual insecticide is used, two insecticide applications per generation may be necessary;
make the first application at about 10 percent egg hatch, which occurs at about 800 DD after
biofix, and the second application 14 days later. Where populations are low or if using a long
residual insecticide (Intrepid, Delegate, Altacor, or Voliam Flexi), one application per
generation should be made anytime between 10 and 30 percent egg hatch of the first
generation, or from 800 to 1,200 DD after biofix.
Second-Generation Recommendation: Population densities of second generation TABM have
been low in recent years since the registration of highly effective new insecticides such as
Altacor, Intrepid, Delegate, and Rimon. In fact, insecticidal control of the second generation
has not been necessary in many orchards when one of these products was used against the first
generation. Not unless pheromone trap captures exceed about 15 moths per trap by 2,600 DD
after biofix (time of 10% egg hatch of the second generation) is an insecticide application
recommended. Control is most important on later maturing apples that are harvested after mid
September.
Mating Disruption
Mating disruption programs consist of emitting relatively large amounts of sex pheromone into
an orchard environment to disrupt the normal mate-location process. Mating disruption
prevents or reduces mating and the subsequent laying of fertile eggs, which effectively reduces
populations below economically damaging levels. It is effective only in blocks of 5 acres or
more. In apples, mating disruption is registered for codling moth and Oriental fruit moth.
Oriental fruit moth is much easier to control with mating disruption compared with codling
moth; use both mating disruption and insecticides against moderate to high codling moth
populations. Mating disruption will not control infestations resulting from immigrating
fertilized female moths; hence, mating disruption alone is not recommended in blocks
located adjacent to a likely source of immigrating moths (such as abandoned orchards or bin
storage areas).
Pheromone Dispensers: A number of companies market pheromone dispensers for mating
disruption, including hand-applied dispensers that emit pheromones for a relatively long period
and sprayable products that last for shorter periods and need to be reapplied. Companies are
now marketing pheromone dispensers that contain both codling moth and oriental fruit moth so
that a single dispenser type can be used for mating disruption of both insects. Dispensers vary
in the amount of pheromone they contain and the length of time during which pheromone is
35
emitted, so read the label beforehand to ensure that dispensers are used properly. Because both
codling moth and Oriental fruit moth are potential pests in the Southeast, it is highly
recommended that dual pheromone dispensers be used.
Timing of Applications: For the codling moth, place pheromone dispensers in the orchard
before adults begin to fly in the spring. First emergence of adults usually begins during late
bloom or petal fall of Delicious cultivars. Hence, dispenser application should be completed
by petal fall. Best results are obtained when dispensers are hung in the upper third of the
canopy, because this is where mating occurs.
The Oriental fruit moth begins to emerge near green tip of Delicious cultivars, so for season-long
control, dispensers should be in the orchard by this time. However, insecticides applied
at petal fall for other insects usually controls this first generation, so if using Oriental fruit
moth dispensers only, application can be delayed until just before emergence of the second- or
third-generation adults (950 and 1850 DD after biofix, respectively). If using sprayable
pheromones for mating disruption, make the initial application when hand-applied dispensers
are applied. If mating disruption is not used against this insect and pheromone trap captures
remain low during the season, a single late-season application in mid to late August will help
to suppress late-season populations.
Monitoring Insects: Monitoring codling moth and Oriental fruit moth populations is of critical
importance to measure the effectiveness of mating disruption and to determine the need for
insecticides. Pheromone traps should be used to monitor moth populations, and fruit should
also be examined at periodic intervals. When properly used, pheromone trapping can be useful
to determine the need for insecticides under mating disruption orchards. Traps should be hung
in the upper one-third of the canopy, because that is where codling moth activity is most
intense. Traps should be hung at a density of no less than one trap per five acres, and
preferably one per three acres, and checked at weekly intervals. Trap captures should be added
each week, and when the cumulative number exceeds an average of three moths per trap, an
insecticide may be necessary. Threshold levels are based on using large delta-style traps and
Trece CM L2 lures, which should be replaced at 12-week intervals.
European Red Mite Management
Several beneficial arthropods can help keep European red mite (ERM) populations below
damaging levels. The most common in the Southeast are the phytoseiid mite (Amblyseius
fallacis) and a complex of generalist predators (such as lady beetles and lacewings). However,
recent research in North Carolina suggests that neither of these predators overwinters to any
significant degree within orchards, so they must be reestablished in orchards in the spring.
Hence, practices that delay the buildup of ERM and enable predators to increase before mites
become a problem will favor biological control. The two most effective practices are applying
a delayed dormant oil spray and avoiding insecticides toxic to these predators.
Monitoring Mite Populations: Use a regular monitoring program to follow the buildup of mite
populations and to determine if and when supplemental applications of a miticide are
necessary to avoid economic damage. Monitor each contiguous block of apples weekly
beginning when adult mites first appear (which may vary from mid May to late June). Within
each block, examine 5 leaves from each of 10 trees with a visor lens or hand lens. Rather than
counting the total number of mites on each leaf, record the number of leaves infested with one
or more mites, and estimate mite density from the table below.
Determining the Need for Miticides: When mite populations reach a density of 5 to 10 mites
per leaf (80 to 90 percent infested leaves), decide whether to rely on biological control or apply
a miticide to prevent mites from increasing to damaging levels. For biological control with
Stethorus punctum to occur, the ratio should be 2.5 S. punctum to 1 ERM. For S. punctum,
count the number of adults and larvae observed during a 3-minute search around the periphery
of mite-infested trees. Count the number of A. fallacis on sample leaves with a visor lens. If the
ratio of A. fallacis to ERM is between 1 to 5 and 1 to 15, biological control is possible. If
neither predator is present at sufficient numbers, and mite populations are between 5 to 10
mites per leaf, apply a miticide.
Where Alternaria blotch is a problem on Delicious apples, biological control is usually not an
option. Alternaria blotch in the presence of mite injury can lead to premature defoliation, so
mite populations must be maintained at very low levels. If preventive control measures are not
used, miticides should be used when mites reach 1-2 mites.
Relationship between European red mite density per leaf and % infested leaves.
% Mite-Infested Leaves
(>1 mite/leaf)
Expected No.
Mites per Leaf
% Mite-Infested Leaves
(>1 mite/leaf)
Expected No.
Mites per Leaf
40
45
50
55
60
65
0.7
0.9
1.1
1.3
1.6
2.0
70
75
80
85
90
95
2.6
3.4
4.7
6.8
11.4
26.4
36
Codling moth degree days (50°F lower base, 88°F upper base) at various daily maximum
and minimum temperatures.
Max
Min
54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96
20 0 1 1 2 2 3 3 4 5 5 6 7 8 9 9 10 11 12 13 14 15 15
22 0 1 1 2 2 3 3 4 6 6 6 7 8 9 10 10 11 12 13 14 15 15
24 0 1 1 2 2 3 4 4 6 6 7 7 8 9 10 11 11 12 13 14 15 16
26 0 1 1 2 2 3 4 4 6 6 7 7 8 9 10 11 12 12 13 14 15 16
28 0 1 1 2 2 3 4 4 6 6 7 8 8 9 10 11 12 13 14 15 15 16
30 0 1 1 2 2 3 4 5 6 6 7 8 9 10 10 11 12 13 14 15 16 16
32 0 1 1 2 3 3 4 5 6 6 7 8 9 10 11 11 12 13 14 15 16 17
34 0 1 1 2 3 3 4 5 6 7 7 8 9 10 11 12 13 14 14 15 16 17
36 0 1 1 2 3 4 4 5 6 7 8 8 9 10 11 12 13 14 15 16 17 17
38 0 1 1 2 3 4 4 5 6 7 8 9 10 11 11 12 13 14 15 16 17 18
40 0 1 2 2 3 4 5 6 6 7 8 9 10 11 12 13 14 15 16 17 17 18
42 0 1 2 2 3 4 5 6 7 7 8 9 10 11 12 13 14 15 16 17 18 19
44 0 1 2 3 3 4 5 6 7 8 9 10 11 12 13 14 15 15 16 17 18 19
46 0 1 2 3 4 5 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
48 1 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 20
50 1 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
52 2 3 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
54 - 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
56 - 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
58 - - 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
60 - - - 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
62 - - - - 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
64 - - - - - 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
66 - - - - - - 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
68 - - - - - - - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
70 - - - - - - - - 18 19 20 21 22 23 24 25 26 27 28 29 30 31
72 - - - - - - - - - 20 21 22 23 24 25 26 27 28 29 30 31 32
74 - - - - - - - - - - 22 23 24 25 26 27 28 29 30 31 32 33
76 - - - - - - - - - - - 24 25 26 27 28 29 30 31 32 33 34
80 - - - - - - - - - - - - 26 27 28 29 30 31 32 33 34 35
Oriental fruit moth degree days (45°F lower base, 91°F upper base) at various daily
maximum and minimum temperatures.
Max
Min
50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96
20 1 1 2 2 3 4 4 5 6 7 8 9 9 10 12 12 13 14 15 16 17 17 18 19
22 1 1 2 2 3 4 4 6 7 7 8 9 10 11 12 12 13 14 15 16 17 18 18 19
24 1 2 2 2 4 4 5 6 7 7 8 10 10 11 12 12 14 15 15 16 18 18 19 20
26 1 2 2 3 4 5 5 6 7 7 8 10 10 11 12 13 14 15 16 16 18 18 19 20
28 1 2 3 3 4 5 5 6 7 8 9 10 10 11 13 13 14 15 16 17 18 19 20 20
30 1 2 3 3 4 5 5 6 7 8 9 10 10 12 13 13 15 16 16 17 19 19 20 21
32 1 2 3 3 4 5 6 6 8 8 9 10 11 12 13 14 15 16 17 18 19 19 20 21
34 1 2 3 3 4 6 6 7 8 8 10 11 11 12 14 14 15 17 17 18 19 20 21 21
36 1 2 3 3 5 6 6 7 8 9 10 11 11 13 14 14 16 17 18 19 19 20 21 22
38 1 2 3 4 5 6 6 7 9 9 10 11 12 13 14 15 16 17 18 19 20 21 21 22
40 1 2 3 4 5 6 6 8 9 9 10 11 12 13 15 15 16 18 18 19 20 21 22 23
42 1 3 4 4 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
44 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
46 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
48 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
50 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
52 - 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
54 - - 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
56 - - - 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
58 - - - - 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
60 - - - - - 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
62 - - - - - - 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
64 - - - - - - - 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
66 - - - - - - - - 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 35
68 - - - - - - - - - 23 24 25 26 27 28 29 30 31 32 33 34 35 36 36
70 - - - - - - - - - - 25 26 27 28 29 30 31 32 33 34 35 36 37 37
72 - - - - - - - - - - - 27 28 29 30 31 32 33 34 35 36 37 38 38
74 - - - - - - - - - - - - 29 30 31 32 33 34 35 36 37 38 39 39
78 - - - - - - - - - - - - - 31 32 33 34 35 36 37 38 39 40 40
80 - - - - - - - - - - - - - - 33 34 35 36 37 38 39 40 41 41
37
Pesticide Resistance Management
General Considerations
Pesticide resistance is a shift in the genetics of a pest population that allows individuals
within a previously susceptible population to survive. Resistant pest populations have
inherited traits that reduce their susceptibility to individual pesticides or groups of
pesticides. Resistance develops in all agricultural pest groups—insects, mites, fungi,
bacteria, nematodes, and weeds. Pesticide-resistant individuals are initially quite rare in
pest populations. However, when a new pesticide is first used, a very low number of
individual pests never previously exposed to the novel chemistry can be expected to be
resistant. The frequency of resistant genes to novel chemistries varies tremendously, but
history makes it clear that resistant individuals should be expected in all pest groups. By
the nature of the process, resistance most often develops to pesticides that are initially
very effective and frequently used.
Pesticide resistance management is an effort to slow or prevent the development of
resistance. It relies on pest management and pesticide-use strategies to prolong the
effective life of pesticides. Resistance management is difficult, especially in high-value
crops such as fruit, where high quality standards and limited numbers of registered
pesticides make the task more challenging.
Managing resistance requires an understanding of the factors that influence its
development. Selection is the process of pesticide-induced selection for resistance.
With regular pesticide use, those rare individuals that are naturally resistant survive and
reproduce more successfully than their susceptible peers. Resistance frequency refers
to the proportion of a pest population that is resistant. Cross resistance refers to a type
of resistance in which a pest population develops resistance to more than one pesticide
within a chemical family (such as organophosphate insecticides or EBDC fungicides).
Multiple resistance involves multiple, independent resistance mechanisms, which often
lead to resistance to chemicals from different families (organophosphate and carbamate
insecticides, dodine and DMI fungicides). Resistance stability is a key factor in
managing resistance. Stability is an estimate of how well resistance persists in a pest
population once the pesticide is no longer used. The rate of reversion to a susceptible
state varies enormously. But when pesticide use ceases, selective pressure for resistance
is removed, and over time resistance will often be reduced. Resistance stability
estimates may allow limited use of resistance-prone compounds.
It is important to emphasize that control failures do not confirm resistance. Other factors
(poor timing, sprayer calibration or coverage, wash-off, high pH in spray tank water,
inappropriate materials, etc.) should be eliminated as causes for control failures before
resistance is seriously considered. Factors influencing the development of resistance can
be grouped into biological and management categories. Biological factors include pest
reproductive rate, mobility of the pest species into and out of untreated areas, and
genetic factors such as number of resistance mechanisms, resistance frequency and
intensity, and resistance stability. Management factors that influence resistance
development include how materials are applied, how often they are used, how long they
persist in the field, treatment thresholds, and strategies for using available pesticides.
Resistance management efforts study specific pest-pesticide interactions and focus on
practical strategies that growers can implement.
Pest management is practical and works in concert with pesticide-use strategies to lessen
resistance selection by facilitating prudent, as-needed pesticide use. Pesticide-use strategies
work best when implemented as a new pesticide comes into commerce. Pesticide
manufacturers, IPM scientists, and growers have come to recognize that using resistance
management from the beginning works best. Collecting baseline susceptibilities, defining
probable resistance problems beforehand, and proposing pesticide-use strategies to forestall
resistance development are the province of manufacturers and IPM scientists. Biologically
and economically sound resistance management plans offered pre-sale give growers the
best hope for managing resistance. Pesticide-use strategies are often grouped as follows: (1)
management by moderation, (2) rotation and mixtures, and (3) saturation.
Moderation means limiting the use of a pesticide. Moderation is employed in concert with
IPM practices, such as using treatment thresholds, spraying only specific pest generations
or growth stages, maintaining unsprayed wild host reservoirs to act as refuges for
genetically susceptible individuals, using pesticides with shorter residual or lower toxicity
to important beneficial populations, etc. Moderation should be used to the fullest extent that
will provide commercially acceptable control.
Rotation, and in some cases mixtures, are the bulwarks of pesticide-use strategies because
an individual pest is less likely to be resistant to two or more differing classes of toxins. In
theory, most individual pests resistant to one pesticide will be killed when exposed to a
different class of toxin. Rotations depend on having effective, labeled materials with
different modes of action. Material cost is a key practical consideration that favors rotation.
Mixtures of fungicides have been used successfully to combat disease resistance, although
cost lessens the attractiveness of this approach. Mixtures of insecticides and miticides have
typically performed poorly. Rotation is seen as the desired approach for insecticides,
miticides, and some fungicides.
Saturation, the use of higher pesticide rates to control resistant individuals, is the least
attractive resistance management approach, although it has been used to manage resistance
to DMI fungicides. Saturation is generally a last resort when there are no other effective,
labeled alternatives. In this scenario, higher rates will often provide control for a time,
although at greater cost. Synergists, chemicals that increase the toxicity of pesticides, have
sometimes been effective in boosting the efficacy of resistance-prone pesticides. As with
simple rate increases, saturation with synergists typically provides only short-term benefits.
Insecticide Resistance Management Strategies
In the southeastern United States, the tufted apple bud moth, codling moth, rosy apple aphid,
and European red mite have developed resistance to one or more pesticides. Currently,
codling moth resistance is most important, but good resistance management strategies are
required to prevent other pests from developing resistance.
Codling Moth
Insecticide-resistant codling moth populations are becoming more prevelant throughout the
Southeast. Resistance to one or more registered insecticides, including Guthion, Intrepid,
Rimon, and Assail, has been detected in a number of orchards in Georgia and North
Carolina. In situations where codling moth resistance occurs, populations usually increase to
large numbers, and frequent insecticide applications at short intervals (7 to 10 days) are
38
necessary at critical times (between 400 and 800 DD after biofix) to prevent damage.
However, such intense insecticide use may lead to higher levels of resistance, so
alternative management strategies should be used in conjunction with insecticides. Using
mating disruption is strongly encouraged as a resistance management tactic, as this will
help reduce population densities more quickly than insecticides alone and, subsequently,
the need for insecticide applications. After two to three years of continuous mating
disruption, codling moth population densities can be reduced so that only one or two total
insecticide applications are needed for season-long control. In addition, make an attempt
to avoid using more than two insecticide applications against a single codling moth
generation by incorporating codling moth virus (Cyd-X or Carpovirusine) applications
into the spray program after two applications have been made. When choosing
insecticides, rotate insecticides with different modes of action against each generation.
For example, make two applications of the same insecticide against the first generation,
but use an insecticide with a different mode of action against the second generation.
Rosy Apple Aphid
The rosy apple aphid has developed widespread resistance to Lorsban, and control
failures with Asana, Ambush, and Diazinon have become more common in recent years.
Consequently, neonicotinoid insecticides are now most commonly used for control. It is
important to remember that all neonicotinoids (Actara, Assail, Calypso, Clutch, and
Provado) have a similar mode of action and should be considered the same material for
rotation purposes.
The two best times to control rosy apple aphid on apple are (1) tight cluster to pink or (2)
petal fall. Do not apply any insecticide with the same mode of action more than once
during this time frame, and if possible do not use the insecticide used for rosy apple aphid
control more than once during the period when the aphids may occur in apple orchards
(through the third or fourth cover spray).
European Red Mite
Avoiding unnecessary miticide applications is the most effective strategy for minimizing
the potential for resistance development. A delayed dormant oil application is highly
recommended to suppress overwintering populations of European red mite and to
improve the potential for biological control to maintain mite populations below damaging
levels. On Delicious cultivars, which are susceptible to alternaria blotch and where
preventive control or low threshold levels are recommended for control of European red
mite, there is a high potential for developing resistant populations. To reduce this
potential, in addition to a delayed dormant oil application, do not use the same miticide in
successive years.
Resistance Management Strategies for Plant Pathogens
Resistance of plant pathogens to pesticides has become widespread over the past 30 years as
site-specific (systemic) chemicals have been developed and used on many crops and against
many pathogens. The broad spectrum protectants (such as captan and mancozeb) that were
used previously had multiple sites of activity in the target pathogens, greatly reducing the
likelihood of resistance development.
Resistance has become a problem in the U.S. in only three pathogens that affect apples
during the growing season: Venturia inaequalis, cause of apple scab; Erwinia amylovora,
cause of fire blight; and Pseudomonas syringae pv. papulans, cause of blister spot.
Resistance of V. inaequalis to dodine (Syllit, initially sold as Cyprex) was first reported in
New York in 1969. It has subsequently been reported in several states in the Northeast and
Midwest but has not been found in orchards in the Southeast. Resistance of V. inaequalis to
the benzimidazole fungicides (benomyl and thiophanate-methyl) was reported shortly after
their introduction in 1971 and became widespread in the eastern U.S., including the
Southeast, in the mid-1970s. As a consequence they are no longer recommended for apple
scab control in the Southeast. The ergosterol biosynthesis inhibiting fungicides (EBI) were
first introduced in the late 1980s, and reduced sensitivity of V. inaequalis has been reported
or suspected in a number of orchards in the Northeast and Midwest, but is not widespread.
Some growers in NC have also had problems controlling scab with EBI fungicides,
suggesting that resistance may be a problem here as well. Resistance of the fire blight
bacterium, E. amylovora, to streptomycin (Agri-mycin 17, Streptrol) is widespread in several
states but has not been reported in the Southeast. Resistance of P. syringae pv. papulans has
been confirmed in an orchard in Tennessee.
To avoid resistance development, minimize the use of fungicides and bactericides in which
resistance is likely to develop. Additionally, combine site-specific fungicides with
protectant fungicides that have broad spectrum activity. Limit dodine applications to two to
three per year. In areas where dodine resistance first became a problem, it was often used
10 to 12 times throughout the growing season. Similarly, limit streptomycin use for fire
blight control to two to four times a year. Make applications only during times favorable for
infection. These periods are characterized by open blossoms, dew or rainfall greater than
0.01 inch, an average daily temperature of 60°F or greater, and the accumulation of at least
198 degree-hours greater than 65°F since the first blossoms opened. Use the ergosterol
biosynthesis inhibiting fungicides only in combination with broad spectrum protectants,
such as captan or EBDC fungicides. Avoid post-symptom applications of site-specific
fungicides, such as dodine and the EBI fungicides, because this sets up an ideal situation for
selection of resistant strains. Good orchard sanitation practices to maintain pathogen
populations at low levels are also an important component of a resistance management
program.
39
Managing Weeds and Preventing the Development of Herbicide
Resistance
Although weed resistance to herbicides is not discussed as often as resistance in insects
and pathogens, cases of weed resistance to herbicides do exist. For example, pigweed
and goosegrass are resistant to dinitroanaline herbicides (Prowl and Surflan).
Johnsongrass is resistant to carboxylase herbicides (Fusilade DX), and horseweed and
pigweed biotypes have developed resistance to glyphosate. Resistance may not be
detected for several years because these resistant weeds produce seed, and then
subsequent generations must establish. Two factors that contribute to the development
of herbicide-resistant weeds are applying herbicides multiple times during the year and
using herbicides that have the same mechanism of control for several consecutive
growing seasons.
Because apples are a perennial crop and have limited herbicide options, techniques like
crop rotation and mechanical cultivation to prevent resistance in annual crops are not
feasible. However, some of the following strategies can help prevent resistance from
developing:
1. Use herbicides ONLY when necessary.
2. Rotate herbicides with different modes of action. For example, do not use simazine
(Princep, Simazine) continuously. Consider other preemergence broadleaf
herbicides. Also avoid making more than two applications of the same herbicide in
the same year.
3. Scout orchards regularly to identify weeds. Respond quickly to changes in weed
population by controlling weeds before they spread through the entire orchard.
4. Use nonselective postemergence herbicides in your weed management program.
Effect of pH on Pesticide Activity
Although the pH of spray water does not directly affect resistance development, it can
affect the activity of some pesticides. The label on dimethoate, phosmet, malathion,
azinphosmethyl, formetanate, ethephon, NAA, and possibly others warns of this effect.
When these materials, except NAA, are exposed to a pH above 7.5, they undergo
hydrolysis and break down to products that are either less effective or not effective.
Excessively acidic conditions may limit uptake of NAA and, therefore, its effectiveness.
The actual rate of breakdown depends on solubility and temperature and the total quantity
broken down during a given period. For example, captan is hydrolyzed very quickly at
alkaline pHs, but because it is very insoluble, the impact of pH is negligible unless captan
is allowed to stand for a week or more. This is also true for chlorothalonil. Hydrolysis
increases with increased temperature. If the time in the spray tank is limited by applying
pesticides immediately, then the quantitative amount broken down is limited.
Additives to the spray tank can also be a factor. Calcium chloride, especially when
concentrated in the tank and applied in a low volume spray, can increase the pH. The
greater the concentration, the greater the alkalinity. The manufacturing process for
calcium chloride leaves residues of free lime (calcium hydroxide). The greater the purity
of the calcium chloride, the lower the content of calcium hydroxide and the lower the
effect on pH.
The water source can be a factor. Although most wells, streams, and rivers in the
southeastern growing region are mildly acidic (6.7 plus or minus 0.2) there are exceptions;
therefore, check pH a few times before regular use. Ponds are more likely to be alkaline,
especially those high in algae and other organisms. These ponds undergo diurnal pH
changes as result of dissolved carbon dioxide. Levels greater than 10 have been observed.
Alkalinity contributed by CO2 is weakly buffered and readily changed by acidifying
agents.
Although not pH-related, some pesticides can be affected by other contaminants in the
water. For example, fenbuconazole, not labeled on apples, is greatly reduced in
effectiveness by suspended particulates. Still other compounds like 2,4-D and
azoxystrobilurin can be very difficult to wash out of the tank and can have a deleterious
effect on apples at very low concentrations.
40
Orchard Floor Management
The best strategy for managing the orchard floor is to use a noncompetitive grass alley
with a vegetation-free strip in the tree row. The vegetation-free strip can be established
and maintained with herbicides as described in this section. The permanent grass sod
between the tree rows will minimize soil erosion, increase soil aeration and
permeability, and support equipment movement through the orchard during wet
weather. The vegetation-free strip eliminates competition for water and nutrients,
minimizes tree damage or loss from voles during the dormant season, and provides
some radiant heat from the soil surface should a spring frost or freeze occur. Herbicides
are directed at the soil and weeds underneath the tree.
The vegetation-free strip method is superior to all other orchard floor management
options. Vegetation under the tree competes for nutrients and water, resulting in reduced
growth, yield, and size of fruit. Another option is the use of organic mulches in the tree
row. Examples of mulching materials include straw, wood chips, and grass residue from
mowing. These mulches will suppress weed emergence, but weed removal by some
means will still be necessary. Mulches can improve the water-holding capacity of some
soils. However, there are several concerns regarding the use of organic mulches. The
most significant problem is that mulches create an ideal habitat for voles. Also,
additional nitrogen may be needed to support the microorganisms that drive
decomposition of organic mulches. In poorly drained or waterlogged soils, organic
mulches increase the likelihood of phytophthora root rot. Mulches can be expensive and
difficult to obtain. Synthetic mulches made from polyethylene, polypropylene, or
polyester can be placed in the tree row around the base of the trunk or as a narrow strip
down the row. Some newer synthetics allow water and air to pass through the mulch.
Herbicide Considerations
To ensure proper herbicide use, always read the manufacturer’s label before application.
All statements on the manufacturer’s label take precedence over any recommendations
in this publication.
It is important that herbicide application equipment be properly calibrated to ensure that
herbicides are applied at the correct rate. For questions about calibrating your sprayer,
contact your county’s Cooperative Extension agent.
Remember that herbicides are applied as a directed spray along each side of the tree
row. Flat fan nozzles are most widely used for applying herbicides. They provide
excellent spray coverage of weeds and come in several sizes with capabilities to apply a
range of spray volumes. Some manufacturers make flat fan nozzles that minimize spray
drift, allowing low-pressure spraying. Investing in such spray nozzles decreases the
likelihood of off-target herbicide movement.
It is advisable to apply white latex paint to the bottom 2 to 3 feet of the tree trunk of
newly planted trees before applying herbicides. Painting the tree trunks reduces the
potential for winter as well as herbicide injury, especially from postemergence
herbicides. Dip a car wash mitt (wear rubber gloves underneath the mitt) in paint and
rub up and down the tree trunk until it is completely painted.
Several herbicides are registered for use in apple orchards. Some are preemergence
herbicides that control weeds that have not emerged, and others are postemergence
herbicides that control emerged weeds. Preemergence herbicides control germinating weed
seeds but usually do not give acceptable control of emerged weeds. Rainfall is needed to
properly activate preemergence herbicides. Rainfall within 7 to 14 days after application
activates most herbicides; however, best control occurs when water (rain or irrigation) is
added within a few days of application. The desired amount of time for rainfall after
application varies by herbicide. Refer to the manufacturer’s label for specific information.
Postemergence herbicides are most effective when applied to actively growing weeds.
Weeds under stress from drought or mowing may not be adequately controlled by
postemergence herbicides. If weeds are stressed from drought, delay herbicide application
until after adequate rainfall when weeds are no longer wilted. If weeds have been mowed,
wait several days to allow regrowth before applying herbicides. Symptoms of herbicide
activity may not be noticeable for up to 14 days after application of glyphosate,
sethoxydim, clethodim, or fluazifop (Roundup, Poast, Select, or Fusilade DX, respectively).
Effects of glufosinate, paraquat, fluroxypyr, and 2,4-D (Rely, Gramoxone Max, Starane
Ultra, and Orchard Master, respectively) are noticeable in 1 to 3 days. Some postemergence
herbicides require the addition of a surfactant or crop oil to improve herbicide activity.
Remember, surfactants and crop oil differ from one another and may not be
interchangeable.
Herbicide Application Timing
The goal of an effective weed management program is to eliminate weed competition the
first 6 to 8 weeks after bud swell and keep the area under the trees weed-free through
harvest. Timing of preemergence (PRE) herbicide application is important in accomplishing
this goal. It has been typical to make a single PRE herbicide application in the spring
followed by postemergence (POST) herbicide applications in the summer as needed.
However, it can be difficult to spray underneath limbs loaded with fruit in mid and late
summer. With appropriate PRE herbicide timing, POST herbicide applications in mid and
late summer can be avoided. Listed below are several PRE herbicide timing options.
1. Fall/Spring Split. One approach is to apply a PRE herbicide with a nonselective
burndown herbicide (glyphosate or paraquat) in the fall after harvest (November). The fall
application will generally provide PRE control into the early summer. When fall PRE
treatment breaks and emerging weeds get 2 to 3 inches tall, another PRE herbicide
application with a burndown herbicide should be applied. Fall herbicide application may be
helpful in managing voles. In areas where erosion is a concern, this option may not be
acceptable.
2. Delayed Preemergence. This approach requires a burndown herbicide application in
March. The burndown herbicide eliminates winter annual weeds until summer annual
weeds emerge in early to mid May. Once summer annual weeds get 2 to 3 inches, apply a
burndown with a PRE herbicide.
3. Spring/Summer Split. (Due to changes in label, this option is available for non-bearing
orchards only.) The registration of Chateau allows for a spring/summer split application
time. However, Chateau is the only herbicide with label flexibility to allow this sequential
application program. Chateau at 6 to 8 ounces per acre with a nonselective postemergence
herbicide can be applied in mid March. This application will last through May and into
June. In June when control from the initial application begins to fail, an additional
application of Chateau at 6 to 8 ounces per acre with either paraquat or Rely for
nonselective postemergence weed control should be applied. The Sinbar label for non-bearing
orchards allows the same use pattern as well.
41
Postemergence herbicides may b